Respuesta :
Area of a rectangle = length * width
f(x) = 2x³ + 30x² – 6x – 90
f(x) = 2(x³ + 15x² – 3x – 45)
f(x) = 2(x²(x + 15) – 3(x+15))
f(x) = 2(x²-3)(x+15)
If width = x+15, then
length = 2(x²-3) = 2x²-6
f(x) = 2x³ + 30x² – 6x – 90
f(x) = 2(x³ + 15x² – 3x – 45)
f(x) = 2(x²(x + 15) – 3(x+15))
f(x) = 2(x²-3)(x+15)
If width = x+15, then
length = 2(x²-3) = 2x²-6