Question

How do you multiply `(3x - 5) ( 3x + 5)`?

Answer 1

`9x^2-25`

Explanation:

`(a+b)(a-b) = a^2-b^2`

substitute `a` with `3x` and `b` with `5`:

`(3x+5)(3x-5) = (3x)^2 - 5^2`

`=9x^2 - 25`

`therefore (3x+5)(3x-5) = 9x^2 - 25`