1- Choice C is correct
The correct answer is $16.88 $62 − $45.12 = $16.88
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2- Choice A is correct
The correct answer is (x – 3) (x − 5) x2 − 8 x + 15 = (x – 3) (x − 5)
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3- Choice A is correct
The correct answer is 6254.7 Underline the tenth place: 6254.7_4164 Look to the right if it is 7 or above, give it a shove. Then, round up to 6254.7
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4- Choice D is correct
The correct answer is 45∘ 90∘ + 45∘=135∘ 180∘ − 135∘=45∘
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5- Choice B is correct
The correct answer is 37.5% 120 × x100 = 45 ⇒ 120 × x = 4500 ⇒ x = 4500120=37.5%
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6- Choice A is correct
The correct answer is 3 y + 6=4 x 3 x + 6=4 x has a graph that is a straight line
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7- Choice C is correct
The correct answer is −12,3 x1,2 = − b ± √b2 − 4 a c2 a a x2 + b x + c = 0 2 x2 − 5 x – 3 = 0 ⇒ then: a = 2,b =− 5 and c = – 3 x = − (− 5) + √(52) − (4) (2) (− 3)2.2=3 x = − (− 5) − √(52) − (4) (2) (− 3)2.2 =− 12
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8- Choice B is correct
The correct answer is 10 C = √(xA − xB)2 + (yA − yB)2 C = √(2 − (− 4))2 + (4 − (− 4))2 C = √(6)2 + (8)2 C = √36 + 64 C = √100=10
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9- Choice D is correct
The correct answer is − 2 x + 153 x2 − 21 Simplify: 43 − 2 x − 39x23 − 73=43 − 2 x − 39x2 − 73=3 (43 − 2 x − 39)x2 − 7 ⇒Simplify: 43 − 2 x − 39=− 2 x + 159 then: 3(− 2 x + 159)x2 − 7=− 2 x + 153x2 − 7=− 2 x + 153 (x2 − 7)=−2 x + 153 x2 − 21
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10- Choice C is correct
The correct answer is $254 42 × $65 = $2730 Payable amount is: $3254 − $2730 = $524
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11- Choice B is correct
The correct answer is 0.058 7120 = 117.14 =0.05833333333 ≅ 0.058
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12- Choice B is correct
The correct answer is 8 and 9 √75 =8.66025 ... then: √75 is between 8 and 9
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13- Choice A is correct
The correct answer is − 5 ± √313 x1,2 = − b ± √b2 − 4 a c2 a a x2 + b x + c = 0 3 x2 + 10 x − 2=0 ⇒ then: a = 3, b =10 and c =− 2 x =− 10 + √102 − (4).(3)(− 2)2.3 =− 5 − √313=−3.523 x =− 10 + √102 − (4).(3).(− 2)2.3 =− 5 + √313=0.189
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14- Choice D is correct
The correct answer is x3 + 3 x2 – 25 x + 21 Use FOIL (First, Out, In, Last) (x + 7)(x2 − 4 x + 3)=x3 − 4 x2 + 3 x + 7 x2 – 28 x + 21=x3 + 3 x2 – 25 x + 21
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15- Choice B is correct
The correct answer is x107 (x5)27=x5 × 27 = x107 = x107
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16- Choice A is correct
The correct answer is 21 Number of squares equal to: 42 × 186 × 6 = 7 × 3=21
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17- Choice D is correct
The correct answer is 40 miles 42 + 47 + 31=120 Average = 1203=40 miles
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18- Choice C is correct
The correct answer is 16 a + b2 = 10 ⇒ a + b = 20 a + b + c3 =12 ⇒ a + b + c =36 20 + c =36 ⇒ c = 36 – 20 = 16
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19- Choice C is correct
The correct answer is −4 Simplify: 6 − 3 x ≤ 18 ⇒− 3 x ≤ 18 – 6 ⇒− 3 x ≤ 12⇒x ≥ −4
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20- Choice B is correct
The correct answer is 9− 3 95 × 9− 8 =95 +(− 8)=9− 3
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20- Choice B is correct
The correct answer is 9− 3 95 × 9− 8 =95 +(− 8)=9− 3
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21- Choice B is correct
The correct answer is 1 − 2 sin2 θ cos 2 θ=cos2 θ − sin2 θ=2 cos2 θ − 1=1 − 2 sin2 θ
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22- Choice B is correct
The correct answer is 35 sin θ = 45 ⇒ we have following triangle, then: c = √52 − 42 = √25 − 16 = √9 = 3 cos θ = 35
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23- Choice B is correct
The correct answer is (x − 4)2 + (y + 1)2 = 2 (x – h)2 + (y – k)2 = r2 ⇒ center: (h,k) and radius: r center: (4,− 1) ⇒ h=4,k=− 1 circumference =4 π⇒ circumference =2 π r=4 π ⇒ r = 2 (x − 4)2 + (y + 1)2 = 4
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24- Choice C is correct
The correct answer is (6,− 16) {4 x + y =8− 8 x − 4 y =16⇒ Multiplication (4) in first equation ⇒ {16 x + 4 y =32 − 8 x − 4 y=16 Add two equations together ⇒ 8 x =48 ⇒x=6 then: y=− 16
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25- Choice B is correct
The correct answer is (6,− 4), √5 (x – h)2 +(y – k)2=r2 ⇒ center: (h,k) and radius: r (x – 6)2 + (y + 4)2=5⇒ center: (6,− 4) and radius: √5
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26- Choice C is correct
The correct answer is √215 sin A= 25 ⇒ we have following triangle, then c = √52 − 22 = √25 − 4 = √21 cos A = adjacenthypotenuse → cos A = √215
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27- Choice A is correct
The correct answer is 729 METHOD ONE log3x = 6 Apply logarithm rule: a = log3(ba) 6 = log336 = log3729 log3x = log3729 When the logs have the same base: logb(f(x)) = logb(g(x)) ⇒ f(x) = g(x) then: x = 729 METHOD TWO We know that: logab = c ⇒ b = ac log3x =6 ⇒ x = 36 = 729
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28- Choice C is correct
The correct answer is 19 2 √129√48 √48 =2 √12 2√129.2 √12 = 19
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29- Choice A is correct
The correct answer is x325 25x3⇒ reciprocal is : x325
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30- Choice C is correct
The correct answer is 64 METHOD ONE log4x=3 Apply logarithm rule: a = logb(ba) 3=log443=log464 log464=log4x When the logs have the same base: logb(f(x)) = logb(g(x)) ⇒ f(x) = g(x) then: x=64 METHOD TWO We know that: logab = c ⇒ b = ac log4x=3⇒x=43=64
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31- Choice A is correct
The correct answer is √32 sin 60^{°} \ = \ \frac{\sqrt{3}}{2}
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32- Choice C is correct
The correct answer is \frac{1}{4} (e^{\ x} \ + \ 3) f (x) \ = \ ln \ (4\ x \ - \ 3) y \ = \ ln \ (4 \ x \ - \ 3 ) Change variables x and y: x \ = \ ln \ (4 \ y \ - \ 3) solve: x \ = \ ln \ (4 \ y \ - \ 3 ) y \ = \ \frac{\ e^{\ x} \ + \ 3}{4 } \ = \ \frac{1}{4} (e^{\ x} \ + \ 3)
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33- Choice D is correct
The correct answer is 13 | \ 15 \ – \ (18 \ ÷ \ | \ 3 \ + \ 6 \ |)| = | (15 \ - \ (18 \ ÷ \ | 9 |))| \ = | \ 15 \ - \ (18 \ ÷ \ 9) \ | = |15 \ - \ 2| \ = \ | \ 13 \ | \ = \ 13
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34- Choice A is correct
The correct answer is - \ 10 \ i \ + \ 71 We know that: i \ = \ \sqrt{\ - \ 1} \ ⇒ \ i^2 \ = \ - \ 1 (- \ 7 \ + \ 2\ i) \ (9 \ + \ 4 \ i) = - \ 63 \ - \ 28 \ i \ + \ 18 \ i \ + \ 8 \ i^2 \ = - \ 63 \ + \ 10 \ i \ - \ 8 \ =- \ 10 \ i \ - \ 71
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35- Choice D is correct
The correct answer is \frac{8}{5} f(x) \ = \ x \ – \frac{4}{5} \ ⇒ \ y \ = \ x \ – \ \frac{4}{5} \ ⇒ \ y \ + \ \frac{4}{5} \ = \ x f^{ \ - \ 1} \ = \ x \ + \ \frac{4}{5} f ^{ \ – \ 1}(2) \ = 2 \ + \ \frac{4}{5} \ = \ \frac{14}{5}
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36- Choice B is correct
The correct answer is \sqrt{3} tan \frac{4 \ π}{3} \ = \ \frac{sin \ \frac{4 \ π}{3}}{cos \ \frac{4 \ π}{3}} = \frac{\frac{ - \ \sqrt{3}}{2}}{- \ \frac{1}{2}} \ = \sqrt{3}
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37- Choice D is correct
The correct answer is -\frac{19}{4} METHOD ONE \log_{5}{(x \ - \ 4)} – \log_{5}{(x \ + \ 3)} \ = \ 1 Add \log_{5}{(x \ + \ 3)} to both sides \log_{5}{(x \ - \ 4)} \ - \ \log_{5}{(x \ + \ 3)} \ + \ \log_{5}{(x \ + \ 3)} \ = \ 1 \ + \ \log_{5}{(x \ + \ 3)} Apply logarithm rule: a \ = \ \log_{b}{b^a} \ ⇒ \ 1 \ = \ \log_{5}{5^1} \ = \ \log_{5}{5} then: \log_{5}{(x \ - \ 4)} \ = \ \log_{5}{5} \ + \ \log_{5}{(x \ + \ 3)} Logarithm rule: \log_{c}{a} \ + \ \log_{c}{b} \ = \ \log_{c}{ab} then: \log_{5}{5} \ + \ \log_{5}{(x \ + \ 3)} = \log_{5}{(5(x \ + \ 3))} \log_{5}{(x \ - \ 4)} \ = \ \log_{5}{(5 \ (x \ + \ 3))} When the logs have the same base: \log_{b}{(f(x))} \ = \ \log_{b}{(g(x))} \ ⇒ \ f(x) \ = \ g(x) (x \ - \ 4) \ = 5 \ (x \ + \ 3) x \ =- \ \frac{19}{4} 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_{5}{x \ - \ 4} \ - \ \log_{5}{x \ +\ 3} \ = \ \log_{5}{\frac{x \ - \ 4} {x \ + \ 3}} \ = \ 1 \ ⇒ \frac{x \ - \ 4}{x \ + \ 3} \ = \ 5^1 \ = \ 5 \ ⇒ \ x \ - \ 4 \ = \ 5 \ (x \ + \ 3) ⇒ \ x \ - \ 4\ = \ 5 \ x \ + \ 15 \ ⇒ \ 5 \ x \ - \ x \ =\ -15 \ - \ 4 \ → \ 4 \ x \ = \ -19 \ ⇒ \ x \ =- \ \frac{19}{4}
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38- Choice B is correct
The correct answer is \frac{2 \ x \ + \ 6}{x^2 \ +\ 3 \ x} (\frac{f}{g}) (x) \ = \ \frac{f(x)}{g(x)} \ = \ \frac{2 \ x \ + \ 6}{x^2 \ +\ 3\ x}
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39- Choice D is correct
The correct answer is 6 y \ = \ m \ x \ + \ b m \ = slop y \ = \ 6 \ x \ + \ 12 m \ = \ 6
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40- Choice D is correct
The correct answer is \frac{ln(8) \ - 1}{7} e^{7 \ x \ + \ 1 } \ = \ 8 If f(x) \ = \ g(x) , then ln(f(x)) \ = \ ln(g(x)) ln(e^{7 \ x \ + \ 1 }) \ = \ ln(8) Apply logarithm rule: \log_{a}{x^b} \ = \ b \log_{a}{x} ln(e^{7 \ x \ + \ 1 }) = (7 \ x \ + \ 1) \ ln(e) (7 \ x \ + \ 1) \ ln \ (e) \ = \ ln \ (8) (7 \ x \ + \ 1) \ ln \ (e) \ = \ (7 \ x \ + \ 1) (7 \ x \ + \ 1) \ = \ ln \ (8) \ ⇒ \ x \ = \ \frac{ln(8) \ - 1}{7}
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