Respuesta :

(2x+7)(2x-7)

4x^2 - 49 is your answer when we FOIL the function.
Multiply the terms using FOIL (first, outside, inside, last).  See attached image.

(2x)(2x) + (2x)(-7) + (7)(2x) + (7)(-7)

4x² - 14x + 14x - 49

4x² - 49