Question

How do you factor `9y^2 - 1`?

Answer 1

`9y^2-1=(3y+1)(3y-1)`

Explanation:

`9y^2-1`
`=(3y)^2-(1)^2`
Using the identity `a^2-b^2=(a+b)(a-b),`
You can further simplify `((3y)^2-(1)^2)` as
`(3y)^2-(1)^2=(3y+1)(3y-1)`