Using Substitution to Check Solutions

Using Substitution to Check Solutions

Introduction

A value is a solution to an equation if it makes the equation true. Substitution can be used to check whether a given value is a solution.

Theory

Ken is checking whether a number solves the equation: x + 8 = 20.

Here, the variable x represents an unknown number. A solution is any number that makes the equation true.

To check whether a given number is a solution, Ken tests different values using substitution.

First, he tests the value x = 5. He...