Worked Example 1
Solve 3x + 5 > 20 and show the answer on a number line.
Solve it exactly like an equation3x > 15, then x > 5
Draw itOpen circle at 5, arrow to the right
Check with two numbers6 works (23 > 20) and 4 correctly fails (17 is not > 20)
Worked Example 2
Solve −2x > 6.
The x term is negativeDividing by −2 is the move that flips the sign
Divide and flipx < −3
Why the flip is necessary3 < 5 becomes −3 > −5. The order of the whole line reverses.
Check itx = −4 works, and x = 0 correctly fails.
1 more worked examples - sign in to see them all.