Some questions on the Praxis Core exam involve a simple plug-and-play approach, where you solve an expression by substituting given values for the variables. Sounds easy, right?
Well, yes and no: as you'll see in the following practice questions, you still need to watch out for double negatives and you have to know your order of operations.
Practice questions
- What is the value of this expression if x = 1, y = –5, z = 8?
7x – 5y + 4z
A. –8 B. 103 C. 64 D. 36 E. –71
- What is the value of this expression if k = –7, m = –10, and n = 11?
Answers and explanations
- The correct answer is Choice (C).Substitute each variable value in for its corresponding variable. Then simplify the result.
- The correct answer is Choice (C).You can substitute each variable value in for its corresponding variable and then simplify the resulting rational expression:
