Question

How do you factor `9x^2 - 25`?

Answer 1

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

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

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