is this correct?

Completely factor the following expression:
64y^2-49z^2
Is the answer: 128 y-49

Find two factors that multiply to the end terms and add to the value of the center term (0).

(8y+7z)(8y-7z)

No, the answer is not 128y - 49. To completely factor the expression 64y^2 - 49z^2, we need to use a special factoring formula called the difference of squares. This formula states that for any two terms a^2 - b^2, we can factor it as (a + b)(a - b).

In this case, we have 64y^2 - 49z^2. We can think of 64y^2 as (8y)^2 and 49z^2 as (7z)^2. So applying the difference of squares formula, we get:

(8y)^2 - (7z)^2
= (8y + 7z)(8y - 7z)

Therefore, the completely factored form of 64y^2 - 49z^2 is (8y + 7z)(8y - 7z).