Multiplication and division inequalities
The question
−3x < −9
−3x < −9
−3x < −9
-9÷−3=3
<→>
x>3
- Solve an inequality like an equation — the same moves on both sides. There is one extra rule at the end.
- Now divide both sides by −3: -9 ÷ −3 = 3.
- Here is the extra rule: dividing both sides by a negative turns the sign round, so < becomes >.
- So x > 3. That is a whole range of numbers, not just one.
How it works.
- 01
Solve an inequality like an equation — the same moves on both sides. There is one extra rule at the end.
- 02
Now divide both sides by −3: -9 ÷ −3 = 3.
- 03
Here is the extra rule: dividing both sides by a negative turns the sign round, so < becomes >.
- 04
So x > 3. That is a whole range of numbers, not just one.