Respuesta :

asadoujohn
1.
4x^2 + 20x
= 4x(x + 5)

2.
x^2 - 12x = 64
x^2 - 12x - 64 = 0
(x - 16)(x + 4) = 0
x - 16 = 0 or x + 4 = 0
x = 16 or x = -4
x = {-4, 16}