And Answers
If x = 4 and y = 2, what is the value of the following expression: 3xy - 12y +
5x
a. -4
b. 10
c. 12
d. 20
e. 24 - ANSWER D: To find the value of this expression, substitute the given values for x and y into the
expression: 3(4)(2) - 12(2) + 5(4) Then, calculate the value of the expression:
3*8 - 12*2 + 5*4
24 - 24 + 20
20
If 0.65x + 10 = 15, what is the value of x?
a. 4.9 2
b. 5.7 8
c. 6.45
d. 7.6 9
e. 8.12 - ANSWER D: First, subtract 10 from both sides to isolate x:
0.65 x + 10 - 10 = 15 - 1 0
0.65 x = 5
Then, divide both sides by 0.65 to solve for x:
0.65 x/0.65 = 5/0.6 5
x = 7.69
Simplify the following: (3x + 5) (4x - 6)
a. 12x2 -38x -30
b. 12x2 + 2x -30
c. 12x2 -2x -1
d. 12x2 +2x + 30
, e. 12x2 + 7x - 30 - ANSWER B: Use the FOIL method (first, outside, inside, and last) to get rid of the
brackets:
12x2 -18x + 20x -30
Then, combine like terms to simplify the expression:
12x2 -18x + 20x -30
12x2 + 2x -30
Simplify the following expression: 50x^18t^6w^3z^20/5x^5t^2w^2z^19
a. 10x13t3wz
b. 10x13t4wz
c. 10x12t4wz
d. 10x13t4wz2
e. 10x12t3w2z2 - ANSWER B: To simplify this expression, it is necessary
to follow the law of exponents that states: xn/xm = xn-m
First, the 50 can be divided by 5: 50/5 = 10
Then, it is simply a matter of using the law of exponents described above to simplify the expression:
10x18-5t6-2w3-2z20-19
10x13t4wz
4! = a. 4
b. 12
c. 16
d. 20
e. 24 -ANSWER E: To calculate the value of this permutation, it is necessary to multiply each number
between one and 4: 1 * 2 * 3 * 4 = 24
If a cube is 5 cm long, what is the volume of the cube?
a. 15 cm3
b. 65 cm3
c. 105 cm3
d. 125 cm3
e. 225 cm3 - ANSWER D: Because it is a cube, it is known that the width and the height of the cube is
also 5cm. Therefore, to find the volume of the cube, we must cube 5cm: 5cm3
This is the same as: 5 * 5 * 5 = 125