ACT Preparation / Unit 11 ACT 1002 short lesson, about 20 seconds
The Square Root Property
Captions available
The idea
When a squared expression stands alone, take the square root of both sides, keeping both signs: if u² = k, then u = ±√k.
In practice
(x − 3)² = 25 gives x − 3 = ±5, so x = 8 or x = −2.
Where people slip
Forgetting the minus sign loses one solution. Isolate the square before taking the root.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Something wrong in this lesson? Flag it · Sources for ACT Preparation