Respuesta :
Rewrite f(x) = 40x + 5x2 as f(x) = 5x^2 + 40x
Factor out the 5: f(x) = 5(x^2 + 8x)
Complete the square: f(x) = 5(x^2 + 8x + 16 - 16) = 5(x+4)^2 - 80 (answer)
Factor out the 5: f(x) = 5(x^2 + 8x)
Complete the square: f(x) = 5(x^2 + 8x + 16 - 16) = 5(x+4)^2 - 80 (answer)