College Algebra / Unit 3 Alg 138 short lesson, about 20 seconds
Checking in the Original Equation
Captions available
The idea
An extraneous solution is a value the solving method produces that fails the original equation; every rational-equation answer gets checked there.
In practice
x/(x − 2) = 2/(x − 2) clears to x = 2, the very value both denominators forbid. No solution.
Where people slip
Check against the original, never the cleared version.
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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