Inequalities and number lines · Optional extension
L022 · Allow 10–15 minutes for learners ready to move on. Answers are available after an attempt.
Stretch
Solve 3−2x<11 and show the solution in words.
Reveal a worked check after attempting
−2x<8, so x>−4; all numbers greater than −4.
Deep challenge
Why does dividing −3x≥12 by −3 reverse the sign? Give a numerical check.
Reveal a worked check after attempting
x≤−4; multiplying an inequality by a negative reverses order, e.g. −3×−4=12 and x=−5 gives 15≥12.