Respuesta :

Answer:

Step-by-step explanation:

f(x) = -5x + 8(7 - x)......when f(x) = 160

160 = -5x + 8(7 - x)

160 = -5x + 56 - 8x

160 - 56 = -5x - 8x

104 = - 13x

-104/13 = x

-8 = x <====