Praxis Math : Praxis Core Skills: Math

Study concepts, example questions & explanations for Praxis Math

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Example Questions

Example Question #1 : How To Reason And Solve One Variable Equations And Inequalities

Solve for \(\displaystyle x\).

\(\displaystyle 9x-18=108\)

Possible Answers:

\(\displaystyle 13\)

Cannot be determined 

\(\displaystyle 14\)

\(\displaystyle 18\)

\(\displaystyle 4\)

Correct answer:

\(\displaystyle 14\)

Explanation:

In order to solve for the variable, \(\displaystyle x\), we need to isolate it on the left side of the equation. We will do this by reversing the operations done to the variable by performing the opposite of each operation on both sides of the equation. 

Let's begin by rewriting the given equation.

\(\displaystyle 9x-18=108\)

Add \(\displaystyle 18\) to both sides of the equation.

\(\displaystyle 9x-18+18=108+18\)

Simplify.

\(\displaystyle 9x=126\)

Divide both sides of the equation by \(\displaystyle 9\).

\(\displaystyle \frac{9x}{9}=\frac{126}{9}\)

Solve.

\(\displaystyle x=14\)

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