###### Alissa Fong

MA, Stanford University
Teaching in the San Francisco Bay Area

Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts

##### Thank you for watching the video.

To unlock all 5,300 videos, start your free trial.

# Difference of Perfect Squares - Problem 1

Alissa Fong
###### Alissa Fong

MA, Stanford University
Teaching in the San Francisco Bay Area

Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts

Share

I know this is difference of perfect squares because it’s a subtraction problem. There is a difference part and is have a perfect square there that’s my constant and I have even exponents. So I know when I’m given a difference of perfect squares like this the factor form looks like a minus b times a plus b.

So for this problem to factor it I’m going to have the square root of this guy which is x plus and minus, I just changed the order. It’s okay with multiplying to change which one’s in which place. I need the square root of 16, 4. This is it, this is my answer.

The factor form of that difference of perfect square is this. I didn’t have to do any fancy Mathy stuff, I didn’t have to do any guessing checking, I just used the shortcut that I knew the square root of that term, I need a plus and a minus and a square to that term. This is how difference of perfect squares saves you time.