Respuesta :

Answer:

25x^2 - 16.

Step-by-step explanation:

(5x+4)(5x-4)

F = 5X*5X = 25X^2

O = 5x * - 4 = -20x

I = 4 + 5x = 20x

L = +4 * -4 = -16

So its

25x^2 - 20x + 20x - 16

= 25x^2 - 16.