1- Choice C is correct
The correct answer is (x \ – \ 6) Factor each trinomial x^2 \ - \ 9 \ x \ + \ 18 \ and x^2 \ – \ 7 \ x \ + \ 6 x^2 \ - \ 9 \ x \ + \ 18 \Rightarrow (x \ – \ 6) \ (x \ - \ 3) x^2 \ – \ 7 \ x \ + \ 6 \Rightarrow (x \ – \ 1) \ (x \ – \ 6)
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2- Choice A is correct
The correct answer is 18 cm^2 a=6 \Rightarrow area of triangle is = \frac{1}{2} \ ( 6\times \ 6) = \frac{36}{2} \ = 18 cm^2
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3- Choice D is correct
The correct answer is 62 degrees 46^{\circ} \ + \ 72^{\circ } = 118^{\circ} 180^{\circ } \ – \ 118^{\circ} = 62^{\circ} The value of the third angle is 62^\circ .
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4- Choice B is correct
The correct answer is x \geq \ 10.5 Simplify: 15 \ – \ \frac{4}{3} \ x \ \leq \ 1 \ \Rightarrow \ – \ \frac{4}{3} \ x \ \leq \ – \ 14 \ \Rightarrow \ – \ x \ \leq\ – \ 10.5 \ \Rightarrow x \geq \ 10.5
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5- Choice A is correct
The correct answer is \frac{1}{2} \frac{1 \ + \ 2\ b}{2 \ b^2} \ = \ \frac{1}{b^2} \Rightarrow (b\neq 0) \ b^2 \ + \ 2 \ b^3 \ = \ 2 \ b^2 \ \Rightarrow 2 \ b^3 \ - \ \ b^2 \ = \ 0 \ \Rightarrow \ b^2 \ (2 \ b \ - \ 1) \ = \ 0 \ \Rightarrow 2 \ b \ - \ 1 \ = \ 0 \ \Rightarrow \ b \ = \frac{1}{2}
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6- Choice D is correct
The correct answer is 5^2 7^{\frac{6}{5} } \ × \ 7^{\frac{4}{5} } = 7^ { \frac{6}{5} \ + \ \frac{4}{5} } = 7^\frac{10}{5} = 7^2
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7- Choice B is correct
The correct answer is b If a^7 \ + \ c^7 \ = \ c^7 \ + \ b^7 then: a^7 \ = \ b^7 \ ⇒ \ a \ = \ b
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8- Choice D is correct
The correct answer is 178.48 Underline the hundredths place: 178.4\underline{\\7}86 Look to the right if it is 7 or above, give it a shove. Then, round up to 178.48
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9- Choice A is correct
The correct answer is (1, 2) y \ = \ 6 \ x \ – \ 1 A. (1, 2) \Rightarrow 2 \ = \ 6 \ – \ 1 \Rightarrow 2 \ ≠ \ 5 B. (– \ 2, \ –\ 13) \Rightarrow \ – \ 13 \ = \ – \ 12 \ – \ 1 \Rightarrow \ – \ 13 \ = \ – \ 13 C. (3, 17) \Rightarrow \ 17 \ = \ 18 \ – \ 1 \Rightarrow 17 = 17 D. (1, 5) \Rightarrow 5 \ = \ 6 \ – \ 1 \Rightarrow \ 5 \ = \ 5
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10- Choice D is correct
The correct answer is 126 210 \ × \ \frac{60}{100} \ = \ 126
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11- Choice B is correct
The correct answer is 35 a \ + \ b \ +\ c = 64 \frac{a \ +\ b \ +\ c \ +\ d}{4} \ =\ 28 \ ⇒\ a \ + \ b \ + \ c \ + \ d \ = \ 112 \ ⇒ \ 64 \ + \ d \ = \ 112 d \ = \ 112 \ – \ 64 \ = \ 48
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12- Choice A is correct
The correct answer is y = 1 \ - \ x Solve for each equation: (2, 3) A. y \ = \ 1 \ – \ x \ ⇒ \ 3 \ = \ 1 \ – \ 3 \ ⇒ \ 3 ≠ - \ 2 B. y \ = 3 \ ⇒ 3 = 3 C. x = 2 \ ⇒ 2 = 2 D. y = x \ + \ 1 ⇒ 3 = 2 \ + \ 1 \ ⇒ \ 3 \ = \ 3
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13- Choice B is correct
The correct answer is 298 If a \ = \ 9 then : 3 \ a^2 \ + \ 7 \ a \ - \ 8 ⇒ 3 \ (9)^2 \ + \ 7 \ (9) \ - \ 8 ⇒ 3 \ (81) \ + \ 63 \ - \ 8 = 298
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14- Choice D is correct
The correct answer is $3,536 32 \ × \ $115 \ = \ $ 3680 Payable amount is: $7216 \ - \ $3680 \ = \ $3536
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15- Choice C is correct
The correct answer is q^{6} (q^3) \ . \ q^3) \ = \ q ^{3 \ + \ 3} \ = \ q^{6}
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16- Choice A is correct
The correct answer is 8 x^2 \ – \ 64 \ = \ 0 \ ⇒ \ x^2 \ = \ 64 \ ⇒ \ x \ = \ 8
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17- Choice C is correct
The correct answer is x^{2} \ - \ 4 \ x \ - \ 12 Use FOIL (First, Out, In, Last) (x \ + \ 2) \ (x \ - \ 6) \ = \ x^2 \ - \ 6 \ x \ + \ 2 \ x \ - \ 12 = x ^2 \ - \ 4 \ x \ - \ 12
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18- Choice B is correct
The correct answer is 72 \frac{54}{9} \ = \ \frac{18}{3} = 6 , \frac{72}{9} \ = \ \frac{24}{3} = 8 , \frac{36}{9} \ = \ \frac{18}{3} =4 , \frac{45}{9} \ = \ \frac{15}{3}= 5 72 is prime number
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19- Choice A is correct
The correct answer is 7.5 If 7.5 \ < \ x \ ≤ \ 11.0 , then x cannot be equal to 7.5
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20- Choice C is correct
The correct answer is 16 If a = \ 8 , then: b = \ \frac{6^2}{3} \ + \ 4 \ ⇒ b = \ \frac{36}{3} \ + \ 4 \ ⇒ b = \ 12 \ + \ 4 \ = \ 16
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21- Choice D is correct
The correct answer is \frac{3}{7} sin B = \ \frac{(the \ length \ of \ the \ side \ that \ is \ opposite \ that \ angle)}{(the \ length \ of \ the \ longest \ side \ of \ the \ triangle)} \ = \ \frac{3}{7}
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22- Choice A is correct
The correct answer is \frac{8}{25} Set of number that are not composite between 1 and 50 : A = \ {1, 2, 3, 5, 7, 11, 13, 17, 19, 23 , 29, 31, 37 , 41,43,47} n (A) = \ 16 \ ⇒ p = \ \frac{16}{50} \ = \ \frac{8}{25}
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23- Choice B is correct
The correct answer is $22,000 loss c (2) \ = \ (2)^2 \ + \ 6\ (2) \ + \ 12 \ = \ 4 \ + \ 12 \ + \ 12 = 28 3 \ × \ 2 = 6 ⇒ 6 \ - \ 28 = \ - \ 22 \ ⇒ \ $22,000 loss
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24- Choice A is correct
The correct answer is\ y = \frac{5}{9} \ x \ + \ \frac{16}{9} - \ 9 \ y = - \ 5 \ x \ - \ 16 \ ⇒ \ y = \frac{- \ 5}{- \ 9} \ x \ - \ \frac{16}{- \ 9} \ ⇒ \ y = \frac{5}{9} \ x \ + \ \frac{16}{9}
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25- Choice C is correct
The correct answer is ln \ (32) \ - \ 4 e^{x \ + \ 4} = 32 ⇒ ln \ (e^{x \ + \ 4}) = \ ln \ (32) (x \ + \ 4) \ ln \ (e) = ln \ (32) x \ + \ 4 = ln \ (32) \ ⇒ \ x \ = \ ln \ (32) \ - \ 4
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26- Choice B is correct
The correct answer is \frac{15}{17} tan \theta \ = \ \frac{8}{15} \ ⇒ we have following triangle, then c \ = \ \sqrt{8^2 \ + \ 15^2} \ = \ \sqrt{64 \ + \ 225} \ = \ \sqrt{289} \ = \ 17 cos \theta \ = \ \frac{15}{17}
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27- Choice D is correct
The correct answer is: M = \ 3 \ + A A = J – \ 5
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28- Choice D is correct
The correct answer is 2 METHOD ONE: \log_{2}{(x \ + \ 6)} \ – \ \log_{2}{(x \ - \ 2)} = 1 Add \log_{2}{(x \ - \ 2)} to both sides: \log_{2}{(x \ + \ 6)} \ – \ \log_{2}{(x \ - \ 2)} + \log_{2}{(x \ - \ 2)} = 1 + \log_{2}{(x \ - \ 2)} And simplify: \log_{2}{(x \ + \ 6)} = 1 + \log_{2}{(x \ - \ 2)} Logarithm rule: a \ = \ \log_{b}{b^a} \ ⇒ \ 1 \ = \log_{2}{2^1} \ = \ \log_{2}{2} then: \log_{2}{(x \ + \ 6)} = \log_{2}{2} \ + \ \log_{2}{(x \ - \ 2)} Logarithm rule: \log_{c}{a} +\log_{c}{b} = \log_{c}{a\ b} then: \log_{2}{2} \ + \ \log_{2}{(x \ - \ 2)} \ = \ \log_{2}{2 \ (x \ - \ 2)}⇒ \log_{2}{(x \ + \ 6)} \ = \ \log_{2}{2 \ (x \ - \ 2)} When the logs have the same base: \log_{b}{(f(x))} \ = \ \log_{b}{(g(x))} \ ⇒ \ f (x) \ = \ g (x) x \ + \ 6 \ = \ 2 \ (x \ - \ 2) \ ⇒ \ x \ + \ 6 \ = \ 2 \ x \ – \ 4 \ ⇒ \ - \ x \ = \ - \ 10 \ ⇒ \ x \ = \ 10 METHOD TWO We know that: \log_{a}{b} \ - \ \log_{a}{c} \ = \ \log_{a}{\frac{b}{c}} and \log_{a}{b} \ = \ c \ ⇒ \ b \ = \ a^c Then: \log_{2}{(x \ + \ 6)} \ - \ \log_{2}{(x \ - \ 2)}=\log_{2}{\frac{x \ + \ 6}{x \ - \ 2}} \ = \ 1⇒ \frac{x \ + \ 6 }{x \ - \ 2} = 2^1 = 2 ⇒ x \ + \ 6 \ = \ 2 \ (x \ - \ 2) ⇒ \ x \ + \ 6 = 2 \ x \ - \ 4 ⇒ 2 \ x \ - \ x \ = \ 6 \ + \ 4 \ ⇒ \ x \ = \ 10
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29- Choice B is correct
The correct answer is 21 C_4^9 \ = \ \frac{9!}{4!(9 \ - \ 3)!} \ = \ \frac {9!}{4! \ 6!} \ = \ \frac{9 \ × \ 8 \ × \ 7 \ × \ 6!}{4! \ × \ 6!} \ = \ \frac{9\ ×\ 8 \ × \ 7 }{4 \ × \ 3 \ × \ 2 \ × \ 1} \ = \ 21
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30- Choice D is correct
The correct answer is x \ ≥ \ 6 The number under the square root symbol must be zero or greater than zero therefore: x \ - \ 6 \ ≥ \ 0 \ ⇒ \ x \ ≥ \ 6 domain of function = \ [6 , \ + \ ∞)
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31- Choice B is correct
The correct answer is (2, 2) \begin{cases}12 \ x \ + \ 4 \ y = 32 \\6 \ x \ - \ 2 \ y = 8 \end{cases}\Rightarrow Multiplication (– \ 2) in first equation \begin{cases}12 \ x \ + \ 4 \ y = 32 \\- \ 12 \ x \ + \ 4 \ y = - \ 16\end{cases} Add two equations together \ ⇒8 \ y = 16 \ ⇒ \ y =2 then: x = 2
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32- Choice C is correct
The correct answer is \frac{7}{4} f (x)=\frac{4 \ x \ - \ 1}{2} ⇒ y=\frac{4 \ x \ - \ 1}{2} \ ⇒ 2 \ y \ = \ 4 \ x \ – \ 1 \ ⇒ 2 \ y \ + \ 1 \ = \ 4\ x \ ⇒ \frac{2 \ y \ + \ 1}{4} \ = \ x f^{ \ - \ 1} = \frac{2 \ y \ + \ 1}{4} \ ⇒ f^{ \ - \ 1} (3) \ = \ \frac{7}{4}
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33- Choice A is correct
The correct answer is – \ x^2 \ – \ 6 \ x \ + \ 4 (g \ + \ f) (x) \ = \ g (x) \ + \ f (x) \ = \ (– \ x^2 \ – \ 3 \ – \ 5 \ x) \ + \ (7 \ - \ x) – \ x^2 \ + \ 4 \ – \ 5 \ x \ – \ x \ = \ – \ x^2 \ – \ 6\ x \ + \ 4
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34- Choice D is correct
The correct answer is (4 , - \ 7 ), 3 \ \sqrt{2} (x \ – \ h)^2 \ + \ (y \ – \ k)^2 \ = \ r^2 \ ⇒ center: (h,k) and radius: r (x \ – \ 4)^2 \ + \ (y \ + \ 7 )^2 \ = \ 18 \ ⇒ center: (4 , - \ 7) and radius: 3 \ \sqrt{2}
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35- Choice A is correct
The correct answer is 4 \ x \ + \ y \ = \ 4 If two lines are parallel with each other, then the slope of the two lines is the same. Then in line y \ = \ 4 \ x , the slope is equal to 4 And in the line 4 \ x \ + \ y \ = \ 4 \ ⇒ y \ = \ 4 \ x \ - \ 4 the slope equal to 4
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36- Choice C is correct
The correct answer is - \ 30 \ ≤ \ x \ ≤ \ 18 \frac{| \ 6 \ + \ x \ |}{8} \ ≤ \ 3 \ ⇒ \ | \ 6 \ + \ x \ | \ ≤ \ 24 \ ⇒ - \ 24 \ ≤ \ 6 \ + \ x \ ≤ \ 24 \ ⇒ - \ 24\ - \ 6 \ ≤ \ x \ ≤ \ 24 \ - \ 6 \ ⇒ - \ 30 \ ≤ \ x \ ≤ \ 18
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37- Choice B is correct
The correct answer is \frac{5}{13} \ + \ i \ \frac{14}{13} If z_1 \ = \ x_1 \ + \ i \ y_1 and z_2 \ = \ x_2 \ + \ i \ y_2 \ ⇒ \frac{z _ 1}{z _ 2} \ = \ \frac{x_1 \ x_2 \ + \ y_1 \ y_2}{x_2^2 \ + \ y_2^2} \ + \ i \ \frac{x_2 \ y_1 \ - \ x_1 \ y_2}{x_2^2 \ + \ y_2^2} In this problem: x_1 \ = \ 4, \ x_2 \ = 2, \ y_1 \ = \ 1, \ y_2 \ = - \ 3 \frac{4 \ +\ i}{ 2 \ - \ 3 \ i} \ = \ \frac{5}{13} \ + \ i \ \frac{14}{13}
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38- Choice D is correct
The correct answer is \sqrt{3} tan ( \frac{π}{3}) \ = \sqrt{3}
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39- Choice B is correct
The correct answer is 2 \ a^2 \ \sqrt{3 \ a} \frac{\sqrt{48 \ a^7 \ b^2}}{\sqrt{2 \ a^2 \ b^2}} = \frac{4 \ a^2 \ b \sqrt{3}}{2 \ a \ b } \ = \ 2 \ a^2 \ \sqrt{3 \ a}
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40- Choice B is correct
The correct answer is 4 \ (2 \ x \ + \ 1) f(x)=\frac{x \ - \ 4}{8} \ ⇒ \ y \ = \ \frac{x \ - \ 4}{8} \ ⇒ \ 8 \ y \ = \ x \ – \ 4 \ ⇒ \ 8\ y \ + \ 4 \ = \ x f ^{ \ - \ 1} \ = \ 8 \ x \ + \ 4 \ = \ 4 \ ( 2 \ x \ + \ 1)
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