Solving inequalities

The question

x + 8 ≤ 20

20−8=12

≤

x≤12

Solve an inequality like an equation — the same moves on both sides. There is one extra rule at the end.
8 was added last, so it comes off first — from both sides: 20 − 8 = 12.
Nothing was divided by a negative here, so the sign has not moved: it is still ≤.
So x ≤ 12. 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
8 was added last, so it comes off first — from both sides: 20 − 8 = 12.
03
Nothing was divided by a negative here, so the sign has not moved: it is still ≤.
04
So x ≤ 12. That is a whole range of numbers, not just one.