Equations and inequalities may contain one or more variables. When you substitute a value for a variable in an equation or inequality, the equation or inequality becomes either true or false.
Look at the balance scale in the interactive. It shows the expression x + 5 on the left and the expression 2x + 3 on the right.
- Substitute 5 for each x in the expressions. What happens when x = 5?
- Is the equation x + 5 = 2x + 3 true?
- Is the inequality x + 5 > 2x + 3 true?
- Is the inequality x + 5 < 2x + 3 true?
INTERACTIVE: Balance Scale X