1- Choice A is correct
The correct answer is 36^\circ The sum of all angles in a quadrilateral is 360 degrees. Let x be the smallest angle in the quadrilateral. Then the angles are: x,\ 2\ x\ ,\ 3\ x\ ,\ 4\ x x\ +\ 2\ x\ +\ 3\ x\ +\ 4 \ x=360→10\ x=360→x=36 The angles in the quadrilateral are: 36^\circ, \ 72^\circ,\ 108^\circ, and 144^\circ
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2- Choice A is correct
The correct answer is 0 Solving Systems of Equations by Elimination Multiply the first equation by - \ 2, then add it to the second equation. \cfrac{\begin{align} - \ 2 \ (2 \ x \ + \ 3 \ y \ = \ 12) \\ 4 \ x \ - \ 4 \ y \ = - \ 16 \end{align}}{} \cfrac{ \begin{align} - \ 4 \ x \ - \ 6 \ y \ = \ - \ 24 \\ 4 \ x \ - \ 4 \ y \ = - \ 16 \end{align} }{\begin{align} - \ 10\ y \ = - \ 40 \\ ⇒ y \ = \ 4 \end{align}} Plug in the value of y into one of the equations and solve for x. 2 \ x \ + \ 3 \ (4)= 12 ⇒ 2 \ x \ + \ 12= 12 ⇒ 2 \ x=0⇒ x= 0
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3- Choice C is correct
The correct answer is \frac{2 \ \sqrt{6}}{5} sin A=\frac{1}{5}⇒ Since sinθ=\frac{opposite}{hypotenuse}, we have the following right triangle. Then: c=\sqrt{5^2\ -\ 1^2 }= \sqrt{25\ -\ 1}=\sqrt{24}=2 \ \sqrt{6} cos A=\frac{2 \ \sqrt{6}}{5}
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4- Choice D is correct
The correct answer is 420 The ratio of boy to girls is 3:4. Therefore, there are 3 boys out of 4 students. To find the answer, first divide the total number of students by 4, then multiply the result by 3. 560 \ ÷\ 4 = 140 ⇒ 140 \ ×\ 3 = 420
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5- Choice A is correct
The correct answer is \frac{2 \ x \ − \ 1}{x^2 \ + \ 2 \ x} (\frac{f}{g})(x) = \frac{f(x)}{g(x)} = \frac{2 \ x \ − \ 1}{x^2 \ + \ 2 \ x}
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6- Choice C is correct
The correct answer is8 Plug in the value of each option in the inequality. A. 1 (1\ -\ 2)^2\ +\ 1>3\ (1) \ -\ 1→2>2 No! B. 6 (6\ -\ 2)^2\ +\ 1>3\ (6)\ -\ 1→17>17 No! C. 8 (8\ -\ 2)^2\ +\ 1>3\ (8)\ -\ 1→37>23 Bingo! D. 3 (3\ -\ 2)^2\ +\ 1>3\ (3)\ -\ 1→2>8 No! E 4 (4\ -\ 2)^2\ +\ 1>3\ (4)\ -\ 1→5>11 No!
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7- Choice D is correct
The correct answer is 25\ π The equation of a circle in standard form is: (x\ -\ h)^2\ +\ (y\ -\ k)^2=r^2, where r is the radius of the circle. In this circle the radius is 5. r^2=25→r=5 (x\ +\ 2)^2\ +\ (y\ -\ 4)^2=25 Area of a circle: A=π\ r^2=π\ (5)^2=25\ π
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8- Choice D is correct
The correct answer is y=4 \ x \ − \ 17 The equation of a line is: y=m \ x \ + \ b, where m is the slope and b is the y-intercept. First find the slope: m=\frac{y_{2} \ - \ y_{1}}{x_{2} \ - \ x_{1} }=\frac{15 \ -\ (- \ 5)}{8 \ - \ 3}=\frac{20}{5}=4 Then, we have: y=4 \ x \ + \ b Choose one point and plug in the values of x and y in the equation to solve for b. Let’s choose the point (3, - \ 5) y=4 \ x \ + \ b→ \ - \ 5=4 \ (3) \ + \ b→ \ - \ 5=12 \ + \ b→b= \ - \ 17 The equation of the line is: y=4 \ x \ - \ 17
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9- Choice D is correct
The correct answer is \frac{7\sqrt{π}}{π} Formula for the area of a circle is: A=π\ r^2 Using 49 for the area of the circle we have:49=π\ r^2 Let’s solve for the radius (r). \frac{49}{π}=r^2→r=\sqrt{\frac{49}{π}}=\frac{7}{\sqrt{π}}=\frac{7}{\sqrt{π}}\ ×\ \frac{\sqrt{π}}{\sqrt{π}}=\frac{7\sqrt{π}}{π}
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10- Choice C is correct
The correct answer is $750 Use simple interest formula: I=prt (I = interest, p = principal, r = rate, t = time) I=(15000) \ (0.025) \ (2)=750
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11- Choice C is correct
The correct answer is x\ ≥9 \ ∪ \ x≤ 1 x\ -\ 5\ ≥\ 4→x\ ≥4\ +\ 5→x≥9 Or x\ -\ 5≤-\ 4→x≤-\ 4\ +\ 5→x≤ 1 Then, solution is: x\ ≥9 \ ∪ \ x≤ 1
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12- Choice C is correct
The correct answer is 48 Length of the rectangle is: \frac{3}{5}\ ×\ 15=9 perimeter of rectangle is: 2\ ×\ (9\ +\ 15)=48
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13- Choice B is correct
The correct answer is 60 First, find the number. Let x be the number. Write the equation and solve for x. 120 \% of a number is 90, then: 1.2\ ×\ x=90 ⇒ x=90 \ ÷\ 1.2=75 80 \% of 75 is: 0.7 \ ×\ 75 = 60
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14- Choice A is correct
The correct answer is 40\% The population is increased by 12\% and 25\%. 12\% increase changes the population to 112\% of original population. For the second increase, multiply the result by 125\%. (1.12) \ ×\ (1.25) = 1.40= 140\% 40 percent of the population is increased after two years.
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14- Choice A is correct
The correct answer is 40\% The population is increased by 12\% and 25\%. 12\% increase changes the population to 112\% of original population. For the second increase, multiply the result by 125\%. (1.12) \ ×\ (1.25) = 1.40= 140\% 40 percent of the population is increased after two years.
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16- Choice E is correct
The correct answer is \frac{4}{19} The probability of choosing a Hearts is \frac{12}{57} = \frac{4}{19}
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17- Choice B is correct
The correct answer is 9\ x^3\ y^5\ -\ 5 \ x^2\ y^3 4\ x^2\ \ y^3\ + \ 5\ x^3\ y^5\ –\ 9\ x^2\ y^3\ +\ 4\ x^3\ y^5\ = 4\ x^2\ y^3\ -\ 9\ x^2\ y^3\ +\ 5\ x^3\ y^5\ + \ 4 \ x^3 \ y^5\ = 9\ x^3\ y^5\ -\ 5 \ x^2\ y^3
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18- Choice C is correct
The correct answer is 142 degree The angle x and 35 are complementary angles. Therefore: x\ +\ 38=180 180^\circ\ - \ 38^\circ=142^\circ
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19- Choice B is correct
The correct answer is \frac{3}{5} tan =\frac{opposite}{djacent}, and tan x=\frac{6}{8}, therefore, the opposite side of the angle x is 6 and the adjacent side is 8. Let’s draw the triangle. Using Pythagorean theorem, we have: a^2\ +\ b^2=c^2→6^2\ +\ 8^2=c^2→36\ +\ 64=c^2→c=10 sin =\frac{opposite}{hypotnuse}=\frac{6}{10} = \frac{3}{5}
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20- Choice E is correct
The correct answer is 36 The sum of supplement angles is 180. Let x be that angle. Therefore, x \ +\ 4\ x\ = 180 5\ x\ = 180, divide both sides by 5: x = 36
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21- Choice D is correct
The correct answer is 4 sin^2 \ a\ + cos^2 \ a=1, then: x\ +\ 1=5, x=4
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22- Choice C is correct
The correct answer is 24\% The question is this: 474.24 is what percent of 624? Use percent formula: part = \frac{percent}{100} \ × whole 474.24 = \frac{percent}{100} \ ×\ 624 ⇒ 474.24= \frac{percent \ ×\ 624}{100} ⇒47424 = percent ×\ 624 ⇒ percent = \frac{47424}{624} = 83.39 47424 is 76 \% of 624. Therefore, the discount is: 100\% \ –\ 76\% = 24\%
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23- Choice B is correct
The correct answer is \frac{\sqrt{5} }{2 \ \sqrt{3}} \ x Simplify the expression. \sqrt{\frac{x^2}{3}\ +\ \frac{x^2}{12}}=\sqrt{\frac{4 \ x^2}{12}\ +\ \frac{x^2}{12}}=\sqrt{\frac{5x^2}{12}}=\sqrt{\frac{5}{12} \ x^2 }= \sqrt{\frac{5}{12}} \ ×\ \sqrt{x^2} = \frac{\sqrt{5}}{\sqrt{12}}\ ×\ \sqrt{x^2}= \frac{\sqrt{5}}{2 \ \sqrt{3}}\ ×\ \sqrt{x^2}=\frac{\sqrt{5} }{2 \ \sqrt{3}} \ x
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24- Choice C is correct
The correct answer is 45,000 Three times of 18,000 is 54,000. One sixth of them cancelled their tickets. One sixth of 54,000 equals 9,000\ (\frac{1}{6} \ ×\ 54000 = 9000). 45,000 \ (54000 \ –\ 9000 = 45000) fans are attending this week
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25- Choice E is correct
The correct answer is 27.5 Let x be the smallest number. Then, these are the numbers: x, x\ + \ 1, x \ + \ 2, x \ + \ 3, x \ + \ 4, x \ + \ 5 average = \frac{sum \ of \ terms}{number \ of \ terms} ⇒ 30 = \frac{x \ + \ (x \ + \ 1) \ + \ (x \ + \ 2) \ + \ (x \ + \ 3) \ + \ (x \ + \ 4)\ + \ (x \ + \ 5)}{6}⇒ 30=\frac{6 \ x \ + \ 15}{6} ⇒ 180 = 6 \ x \ + \ 15 ⇒ 165 = 6 \ x ⇒ x=27.5
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26- Choice D is correct
The correct answer is − \ \frac{1}{2} The equation of a line in slope intercept form is: y=m \ x \ + \ b Solve for y. 4 \ x \ - \ 2 \ y=16 ⇒ - \ 2 \ y=16 \ - \ 4 \ x ⇒ y=(16 \ - \ 4 \ x) \ ÷ \ (- \ 2) ⇒ y=2 \ x \ - \ 8 The slope is 2. The slope of the line perpendicular to this line is: m_{1} \ × \ m{2} = \ - \ 1 ⇒ 2 \ × \ m_{2} = \ - \ 1 ⇒ m_{2} = \ - \ \frac{1}{2}
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27- Choice E is correct
The correct answer is 30 Plug in the value of x and y. x=2 and y=-\ 2 5\ (x\ -\ 2\ y)\ +\ (2 \ - \ x)^2=5\ (2\ -\ 2(-\ 2))\ +\ (2\ -\ 2)^2=5\ (2\ +\ 4)\ +\ (0)^2 = 30\ +\ 0=30
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28- Choice E is correct
The correct answer is 3.2\ ×\ 10^5 320000=3.2\ ×\ 10^5
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29- Choice C is correct
The correct answer is \frac{y}{8} Solve for x. \sqrt{8 \ x}=\sqrt{y} Square both sides of the equation: (\sqrt{8 \ x})^2=(\sqrt{y})^2 , 8\ x=y , x=\frac{y}{8}
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30- Choice A is correct
The correct answer is Length of AD equal to length BC In any rectangle opposite sides are equal.
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31- Choice A is correct
The correct answer is 2 cm Formula for the Surface area of a cylinder is: S A =2 \ π \ r^2 \ + \ 2 \ π \ r \ h→ 48 \ π=2 \ π \ r^2 \ + \ 2 \ π \ r \ (10)→ r^2 \ + \ 10 \ r \ - \ 24=0 Factorize and solve for r. (r \ + \ 12)(r \ - \ 2)=0→r=2 or r= \ - \ 12 (unacceptable)
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32- Choice D is correct
The correct answer is 8, 4 (x\ +\ 2)\ (x\ +\ p)=x^2\ +\ (2\ +\ p)x\ +\ 2\ p→2\ +\ p=6→p=4 and r=2\ p=8
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33- Choice E is correct
The correct answer is (1,6), (2,5), (− \ 5,8) Since the triangle ABC is reflected over the y-axis, then all values of y’s of the points don’t change and the sign of all x’s change. (remember that when a point is reflected over the y-axis, the value of y does not change and when a point is reflected over the x-axis, the value of x does not change). Therefore: (− \ 1,6) changes to (1, 6) (− \ 2, 5) changes to (2, 5) (5, 8) changes to (− \ 5, 8)
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34- Choice E is correct
The correct answer is 170 miles Use the information provided in the question to draw the shape. Use Pythagorean Theorem: a^2 \ + \ b^2 = c^2 80^2 \ + \ 150^2 = c^2 ⇒ 6400 \ + \ 22500 = c^2 ⇒ 28900 = c^2 ⇒ c = 170
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35- Choice A is correct
The correct answer is \frac{1}{10} Write the ratio of 2 \ a to 3 \ b. \frac{2 \ a}{3 \ b}=\frac{1}{15} Use cross multiplication and then simplify. 2 \ a \ × \ 15=3 \ b \ ×\ 1→30 \ a=3 \ b→a=\frac{3 \ b}{30}=\frac{b}{10} Now, find the ratio of a to b. \frac{a}{b}=\frac{\frac{b}{10}}{b}→\frac{b}{10} \ ÷\ b=\frac{b}{10} \ × \ \frac{1}{b}=\frac{b}{10 \ b}=\frac{1}{10}
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36- Choice D is correct
The correct answer is $4.5 Let x be the cost of one-kilogram orange, then: 4\ x\ + \ (2 \ × \ 4.2)=25.4→ 4\ x\ +\ 8.4=25.4→4\ x=25.4\ -\ 8.4→4\ x=18→x=\frac{18}{4}=$4.5
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37- Choice E is correct
The correct answer is 7 Let x be the number of adult tickets and y be the number of student tickets. Then: x \ + \ y =12, \ 12.50 \ x \ + \ 7.50y=125 Use elimination method to solve this system of equation. Multiply the first equation by - \ 7.5 and add it to the second equation. - \ 7.5 \ (x \ + \ y=12), \ - \ 7.5 \ x \ - \ 7.5 \ y= \ - \ 90, 12.50 \ x \ + \ 7.50y=125 5 \ x=35, \ x=7 There are 7 adult tickets and 5 student tickets.
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38- Choice E is correct
The correct answer is \begin{bmatrix}-\ 4&5\\ 4&-\ 8\end{bmatrix} First, find 2 A. A=\begin{bmatrix}-\ 1 & 3\\ 1 & -\ 3\end{bmatrix} 2A=2\ ×\ \begin{bmatrix}-\ 1&3\\ 1 & -\ 3\end{bmatrix}=\begin{bmatrix} -\ 2& 6\\ 2 & -\ 6\end {bmatrix} Now, solve for 2 A - B. 2 A-B=\begin{bmatrix} -\ 2&6 \\ 2& -\ 6\end {bmatrix}\ -\ \begin{bmatrix} 2&1\\ -\ 2 & 2\end{bmatrix}=\begin{bmatrix}-\ 2 \ -\ 2 & 6 \ -\ 1\\ 2\ -\ (-\ 2) & -\ 6\ -\ 2\end{bmatrix}=\begin{bmatrix}-\ 4&5\\ 4&-\ 8\end{bmatrix}
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39- Choice C is correct
The correct answer is x ^ {\frac{15}{7}} (x^5)^{\frac{3}{7}} = x^{5 \ ×\ \frac{3}{7}} =x ^ {\frac{15}{7}}
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40- Choice A is correct
The corrcet answer is 3,375 If the length of the box is 45, then the width of the box is one third of it, 15, and the height of the box is 5 (one third of the width). The volume of the box is: V = lwh = (45)\ (15)\ (5) = 3,375
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41- Choice D is correct
The correct answer is 2 The amplitude in the graph of the equation y=a cos b\ x is a. (a and b are constant) In the equation y\ -\ 1=2 cos 3\ x, the amplitude is 2.
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42- Choice D is correct
The correct answer is \frac{\sqrt{3}}{2} The relationship among all sides of right triangle 30^\circ \ - \ 60^\circ \ - \ 90^\circ is provided in the following triangle: cos of 30^\circ equals to:\frac{adjacent}{hypotenuse}=\frac{x \ \sqrt{3}}{2\ x}=\frac{\sqrt{3}}{2}
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43- Choice E is correct
The correct answer is 43 The area of rectangle is: 8 \ × \ 4=32 cm^2 The area of circle is: π \ r^2=π \ × \ ( \frac{10}{2})^2=3 \ × \ 25=75 cm^2 Difference of areas is: 75 \ - \ 32=43
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44- Choice A is correct
The correct answer is 62.84 kg average = \frac{sum \ of\ terms }{number \ of\ terms} The sum of the weight of all girls is: 18 \ ×\ 60 = 900 kg The sum of the weight of all boys is: 37 \ ×\ 64 = 2368 kg The sum of the weight of all students is: 900 \ +\ 2368 = 3268 kg average = \frac{3268}{52} = 62.84
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45- Choice A is correct
The correct answer is January and February First find the number of pants sold in each month. A. January: 110, February: 88, March: 90, April: 70, May: 85, June: 65 Check each option provided. January and February, (\frac{110 \ - \ 88}{110}) \ × \ 100=\frac{22}{110} \ × \ 100=20\% B. February and March, there is an increase from February to March. C. March and April (\frac{90 \ - \ 70}{90}) \ × \ 100=\frac{20}{90} \ × \ 100=22.22\% D. April and May: there is an increase from April to May May and June (\frac{85 \ - \ 65}{85}) \ × \ 100=\frac{20}{85} \ × \ 100=23.53\%
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46- Choice C is correct
The correct answer is 147.5, 30 Let’s order number of shirts sold per month: 130,140,145,150,160,170 median is: \frac{145 \ + \ 150}{2}=147.5 Let’s list the number of shoes sold per month: 20,25,25,35,35,40 mean is: \frac{20 \ + \ 25 \ + \ 25 \ + \ 35 \ + \ 35 \ + \ 40}{6}=\frac{180}{6}=30
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47- Choice C is correct
The correct answer is 50 Let x be the number of shoes need to be added in April. Then: \frac{70}{20 \ + \ x}=(\frac{5}{17}) \ (\frac{85}{25}) →\frac{70}{20 \ + \ x}=\frac{425}{425}=1→ 70=20 \ + \ x→x=50
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48- Choice B is correct
The correct answer is 5 3125=5^5→5^{ \ x}=5^5→x=5
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49- Choice D is correct
The correct answer is 18 Plug in the value of x in the equation and solve for y. 3 \ y=\frac{2 \ x^3}{5} \ + \ 4→ 3 \ y =\frac{2(5)^3}{5} \ + \ 4→ 3 \ y=\frac{2 \ (125)}{5} \ + \ 4→ 3 \ y= 50 \ + \ 4=54 3 \ y = 54→y=18
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50- Choice B is correct
The correct answer is \frac{15 \ \sqrt{3}}{2} Based on triangle similarity theorem: \frac{a}{a\ +\ b}=\frac{c}{4}→c=\frac{4\ a}{a\ +\ b}=\frac{4\sqrt3}{4\sqrt3}=1→ area of shaded region is: (\frac{c\ +\ 4}{2})\ (b)=\frac{5}{2}\ ×\ 3\sqrt{3}=\frac{15 \ \sqrt{3}}{2}
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51- Choice E is correct
The correct answer is \sqrt{6}\ - \ 1 x_{1,2} =\frac{ -\ b \ ±\ \sqrt{b^2\ -\ 4\ a\ c }}{2\ a} a\ x^2\ +\ b\ x\ +\ c = 0 x^2 \ +\ 2\ x\ –\ 5 = 0 ⇒ then: a = 1, b = 2 and c = \ – \ 5 x =\frac{ -\ 2 \ +\ \sqrt{2^2 \ -\ 4 .1 .-5}}{2 .1} = \sqrt{6} \ –\ 1 x = \frac{-\ 2 \ -\ \sqrt{2^2 \ -\ 4 .1 .-\ 5 }}{2 .1} = –\ 1 \ –\ \sqrt{6}
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52- Choice B is correct
The correct answer is 110 \ x \ + \ 16,000 \ ≤ \ 23,000 Let x be the number of shoes the team can purchase. Therefore, the team can purchase 110 \ x. The team had $23,000 and spent $16000. Now the team can spend on new shoes $7000 at most. Now, write the inequality: 110 \ x \ + \ 16,000 \ ≤ \ 23,000
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53- Choice B is correct
The correct answer is \frac{3}{x^2} \ + \ 5 f(g(x))=3 \ × \ (- \ \frac{1}{x})^2 \ + \ 5=\frac{3}{x^2} \ + \ 5
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54- Choice C is correct
The correct answer is 64 m^2 Let L be the length of the rectangular and W be the with of the rectangular. Then, L=3 \ W \ + \ 4 The perimeter of the rectangle is 40 meters. Therefore: 2 \ L \ + \ 2 \ W=40 L \ + \ W=20 Replace the value of L from the first equation into the second equation and solve for W: (3 \ W \ + \ 4) \ + \ W=20→4 \ W \ + \ 4=20→4 \ W=16→W=4 The width of the rectangle is 4 meters and its length is: L=3 \ W \ + \ 4=3 \ (4) \ + \ 4=16 The area of the rectangle is: length × width = 4 \ × \ 16 = 64
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55- Choice A is correct
The correct answer is 120 Here is the list of all prime numbers between 20 and 40: 23, 29, 31, 37 The sum of all prime numbers between 20 and 40 is: 23 \ + \ 29 \ + \ 31 \ + \ 37 = 120
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56- Choice D is correct
The correct answer is i\ +\frac{ 3}{4} To simplify the fraction, multiply both numerator and denominator by i. \frac{4\ -\ 3\ i}{-\ 4\ i}\ ×\ \frac{i}{i}=\frac{4\ i\ -\ 3\ i^2} { -\ 4\ i^2} i^2\ -\ 1, Then: \frac{4\ i\ -\ 3 \ i^2}{-\ 4\ i^2 }=\frac{4\ i\ -\ 3(-\ 1)}{-\ 4(-\ 1)}=\frac{4\ i\ +\ 3}{4}=\frac{4\ i}{4}\ +\ \frac{3}{4}=i\ +\frac{ 3}{4}
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57- Choice E is correct
The correct answer is 0, -\ 2 , -\ 3 Frist factor the function: f(x)=x^3\ +\ 5\ x^2\ +\ 6\ x\ =x\ (x\ +\ 2)\ (x\ +\ 3) To find the zeros, f(x) should be zero. f(x)=x \ (x\ +\ 2)\ (x\ +\ 3)=0 Therefore, the zeros are: x=0 (x\ +\ 2)=0 ⇒ x= -\ 2 (x\ +\ 3)=0 ⇒ x= -\ 3
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58- Choice D is correct
The correct answer is 24 Let x be the length of AB, then: 12=\frac{x×3}{2}→x=8 The length of AC =\sqrt{6^2\ +\ 8^2 }=\sqrt{100}=10 The perimeter of ∆ABC=6\ +\ 8\ +\ 10=24
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59- Choice D is correct
The correct answer is 12.5 feet Use formula of rectangle prism volume. V = (length) (width) (height) ⇒ 5000 = (20) \ (20) (height) ⇒ height = 5000 \ ÷ \ 400 = 12.5
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60- Choice B is correct
The correct answer is 25 \ x^8 y=(-\ 5 \ x^4)^2=(-\ 5^2) \ (x^4)^2= 25 \ x^8
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