Free Compass Math Practice Questions on Substituting
Values Into Algebraic Expressions with Solutions and Explanations - Sample 11
Solutions with detailed explanations to compass math test practice questions in sample 11.

  1. What is the value of 2(x3 - y2) + 2(x3 + y2) for x = 2 and y = -4?

    Solution

    Substitute x and y by their values and simplify

    2(23 - (-4)2) + 2(23 + (-4)2)

    = 2(8 - 16) + 2(8 + 16)

    = -16 + 48 = 32

  2. If x = 3, what is the value of 6 / x + 4x - 20?

    Solution

    Substitute x by its value and simplify

    6 / x + 4x - 20

    = 6/3 + 4(3) - 20

    = 2 + 12 - 20 = -6

  3. The surface area A of a cylindrical container is given by the formula

    A = 2 pi r2 + 2 pi r h


    where r is the radius, h is the height of the container and h its height and pi is a constant which can be approximeted by 3.14. Which of the values below is closeset to the area of a container whose radius is 10 cm and its height 5 cm?

    A) 628
    B) 1256
    C) 314
    D) 3140
    E) 942

    Solution

    Substitute r, h and pi by their values in the formula for the area.

    A = 2(3.14)(10)2 + 2(3.14)(10)(5)

    = 628 + 314 = 942

  4. If x = - 2 and y = 3, what is the value of - x- y?

    Solution

    Substitute x and y by their values and simplify

    - x- y

    = - (-2)(-3)

    = - 1 / (-2)3

    = - 1 / -8 = 1 / 8

  5. If y = -3, what is the value of (y3 - 3) / (- y + 3)?

    Solution

    Substitute y by its values and simplify

    (y3 - 3) / (- y + 3)

    = ((-3)3 - 3) / (- (-3) + 3)

    simplify

    = (-27 - 3) / (3 + 3)

    = -30 / 6 = - 5

  6. What is the value of 3 x3 - 2 x2 + 2 for x = - 2?

    Solution

    Substitute x by its values in the given expression

    3 x3 - 2 x2 + 2

    = 3 (-2)3 - 2 (-2)2 + 2

    Simplify

    = 3(-8) - 2(4) + 2

    = -24 -8 + 2 = -30

  7. If x = 2.7, what is the value of x + 0.75(x - 1.5) + 1.2?

    Solution

    Substitute x by its values in the given expression and simplify

    x + 0.75(x - 1.5) + 1.2

    = 2.7 + 0.75(2.7 - 1.5) + 1.2

    = 4.8

  8. If x = - 0.07 and y = 1.2, what is the value of x y - 0.2 (y - x)?

    A) 0.338
    B) - 0.338
    C) 0.3
    D) - 0.3
    E) 0.338

  9. At normal resting heart rates, the mean arterial pressure MAP can be approximated by the simple formula

    MAP = DP + (1/3)( SP - DP )


    where DP is the diastolic pressure and SP systolic pressure. Find the mean arterial pressure MAP, rounded to the nearest unit, for a person with systolic pressure SP of 101 mmHg and a diastolic pressure DP of 72 mmHg.

    A) 85
    B) 100
    C) 90
    D) 80
    E) 82

  10. What is the value of 3 / (x - 4 y) + 2 / (0.5 x + 8 y) for x = - 2 and y = - 0.25?

    A) 11 / 3
    B) 3 / 11
    C) - 3 / 11
    D) - 11/3
    E) 3

Answers to the Above Questions
  1. B
  2. C
  3. E
  4. A
  5. D

  6. D
  7. A
  8. B
  9. E
  10. D

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