College Algebra / Unit 3 Alg 165 short lesson, about 20 seconds
Compound Inequalities
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The idea
A compound inequality chains two conditions around one expression; every solving move applies to all three parts at once.
In practice
−3 < 2x + 1 ≤ 7: subtract 1 and divide by 2 throughout, giving −2 < x ≤ 3 — the interval (−2, 3].
Where people slip
Whatever touches the middle touches both ends.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
- Nothing. This is a starting point.
Unlocks
- Nothing yet depends on this.
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