Question

Factor completely 64x2– 49

Answer 1

`(8x+7)(8x-7)`

Explanation:

Rewrite the expression as:

`64x^2-49=(8x)^2-7^2`

We obtained a difference of two squares, so we can use the next formula:

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

In this case:

`a=8x`

and

`b=7`

Therefore:

`(8x)^2-7^2=(8x+7)(8x-7)`

Answer 2

The theorem is: a^2 - b^2 = (a+b) (a-b)
So, let's do this:

64x^2 - 49=
(8x)^2 - (7)^2=
(8x+7) (8x-7)