Question

How do you factor `4x^2 - 16`?

Answer 1

So, `4x^2 -16 =color(blue)((2x+4)(2x-4)`.

Explanation:

`4x^2 - 16` is of the form `color(blue)(a^2 - b^2` (where `a=2x , b=4)` , and as per the identity:
`color(blue)(a^2 - b^2= (a+b)(a-b)`

So, `4x^2 -16 =color(blue)((2x+4)(2x-4)`.