College Algebra / Unit 2 Alg 090 short lesson, about 20 seconds
Factoring a Difference of Squares
Captions available
The idea
A difference of squares factors into conjugate binomials: a² − b² = (a + b)(a − b).
In practice
9x² − 16 is (3x)² minus 4², so it factors as (3x + 4)(3x − 4). Multiply back and the middle terms cancel.
Where people slip
Both terms must be perfect squares joined by a minus sign.
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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