Year 7 Interactive Maths - Second Edition

## Solution of Equations

Finding the value of a pronumeral that makes a statement true is said to be solving the equation.

In the following sections, we will consider solving equations involving addition, subtraction, multiplication and division.

### Equations Involving Addition

Consider the equation

If we subtract 8 from both sides of the equation, then we obtain:

We notice that the statement

remains a true statement when 8 is subtracted from both sides of the equation.

This suggests that equations behave like a balance.  If the same mass is taken away from both scales of a balance, it still remains balanced.  This implies that we can subtract the same number from both sides of an equation to get a new equation.

Consider the equation x + 3 = 7.

###### From the preceding discussion, we can state that:

The same number can be subtracted from both sides of an equation.

#### Example 3

##### Solution:

###### Key Terms

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