ACT Preparation / Unit 9 ACT 0820 short lesson, about 20 seconds
Compound Inequalities
Captions available
The idea
A compound inequality joins two conditions: with and, both hold, as in a < x < b; with or, either may. Apply each step to all three parts.
In practice
−1 ≤ 2x + 3 < 9 gives −4 ≤ 2x < 6, so −2 ≤ x < 3.
Where people slip
As an interval, [−2, 3): the bracket includes −2; the parenthesis excludes 3.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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