Year 9 Interactive Maths - Second Edition

Dividing Each Side of an Inequality by a Negative Number

Consider the inequality

20 > 10

Let us consider another example.

Consider the inequality

10 < 20

In general:

If both sides of an inequality are divided by the same negative number, then:

Example 28

Solution:

Example 29

Solution:

Just to recap the foregoing discussion:

• The same number can be added to or subtracted from both sides of an inequality.
• Both sides of an inequality can be multiplied or divided by the same positive number.
• If an inequality is multiplied (or divided) by a negative number, then: