We’ve all learned what factoring is in at least third grade. The simple explanation taught to us at this grade period is the following… Factoring deals with having a number, x and figuring out how many numbers multiplied could give you the value x.

A more advanced method of this method is to factor using the difference of two squares. It’s called this because this kind of factors deals with square roots of 2. Which can be looked at as the sides of a perfect square. It’s kind of hard to explain so I will just show an example.

(x+y)(x-y)

x^2+ -xy+xy-y^2

x^2+y^2

Now to see a factor with actual numbers.

Factor: x^2-81y

Think: What gives me zero when added and multiplied gives me 81?

Answer: 9 + (-9) = 0, 9(-9)=81

Complete factor: (x+9y)(x-9y)

Can anyone come up with an example ?

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You learned factoring the third grade?! I was still learning how to multiply in third grade.All the same, nice explanation of the difference of two squares.

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