GED Math Extra Prep: Order of Operations - dummies

GED Math Extra Prep: Order of Operations

By Consumer Dummies

The GED Math test has a lot of questions where you’ll need to solve a mathematical expression (no surprise there), so you’ll need to know your order of operations to get the right answer.

Practice Questions

  1. What is the value of 6x – 3y2 when x = 12 and y = –5?

    A. –153
    B. 297
    C. –3
    D. 147

  2. Simplify the following:

    GED_2001

    A. 35
    B. 45
    C. 50
    D. 500

Answers and Explanations

  1. The correct answer is C.

    Substitute the given values of x and y into the expression:

    6x – 3y2 = 6(12) – 3(–5)2

    Then use the correct order of operations to simplify: Remember PEMDAS — (Parentheses, then Exponents, then Multiplication and Division, and then Addition and Subtraction). So first evaluate the exponent, then perform the multiplication, and finally perform the subtraction:

    GED_2002

    Hence, Choice (C) is correct.

  2. The correct answer is C.

    Note that anything to the zero power equals 1, so you can simplify the expression as follows:

    GED_2003

    Then use the correct order of operations to simplify further: Remember PEMDAS (Parentheses, then Exponents, then Multiplication and Division, and then Addition and Subtraction). First, find the value of the terms within the parentheses by evaluating the exponent before adding the 1:

    GED_2004

    Then perform the multiplication to get 50. Hence, Choice (C) is the correct answer.