Question

Re-write the quadratic function below in Standard Form

y=−2(x+5)(x−4)

Answer 1

Answer: y = -2x^2 - 2x + 40

Step-by-step explanation:

First we can distribute the -2 onto x and 5 which leaves us with

y = (-2x - 10)(x - 4)

Then we use FOIL to multiply (-2x-10) and (x-4)

-2x * x = -2x^2

-2x * -4 = 8x

-10 * x = -10x

-10 * -4 = 40

That leaves us with y = -2x^2 + 8x -10x + 40

Combining like terms gives us y = -2x^2 - 2x +40

If you are unfamiliar with FOIL please look up a video.