Question

What is the factorization of the expression below?

16x^2 - 49
A. (8x + 7)(2x-7)
O B. (4x + 7)(4x - 7)
O C. (8x-7)(2x-7)
O D. (4x-7)(4x-7)

Answer 1

B

Explanation:

There is no number between 16x and 49. So only think about the number being squared for 49; which is 7.

Then 49 is negative, so you must have both positive and negative signs in both parenthesis. Otherwise, positive times positive is positive, and negative times negative is also positive.

4x4 is 16. That's why you put fours in front of Xs.

I am sorry for getting this wrong (if i did)

Answer 2

B

Explanation:

16 x² - 49 ← is a difference of squares and factors in general as

a² - b² = (a + b)(a - b), thus

16x² - 49

= (4x)² - 7²

= (4x + 7)(4x - 7) → B