How to factor difference of squares

1. Difference of squares
How to factor difference of squares

2. What is a difference of squares?
 This is a binomial where each term is a perfect square separated by a subtraction sign. 𝑎2
− 𝑏2

Examples Non-examples Why?
𝑥2 − 25 𝑥2 + 25 Plus sign
4𝑥2
− 9 3𝑥2
− 9 3 isn’t a perfect square
16𝑥2 − 81 16𝑥 − 81 X isn’t a perfect square
𝑥2 − 1 𝑥2 − 1𝑥 − 1 3 terms

3. How to factor…
 Factoring a difference of squares is pretty easy! 𝑎2
− 𝑏2
= (𝑎 − 𝑏)(𝑎 + 𝑏)
 In the past, I have noticed students have trouble with the formula so I have added something to
it to help you.
𝑎2
𝑥2
− 𝑏2
= 𝑎𝑥 − 𝑏 𝑎𝑥 + 𝑏
 This formula seems to help students with the ‘a’ term

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