Question

What polynomial has roots of -5, -4, and 1?

Answer 1

answer choices:

x^3 - 8x^2 - 11x + 20

x^3 - x^2 + 22x + 40

x^3 + x^2 - 22x - 40

x^3 + 8x^2 + 11x - 20

Answer 2

Plug each of them into each equation. Whichever one is 0 for those 3 numbers is your answer.

Answer 3

(x + 5)(x + 4)(x - 1)

(x^2 + 9x + 20)(x - 1) = x^3 - x^2 + 9x^2 - 9x + 20x - 20

x^3 + 8x^2 + 11x - 20

Answer 4

I guess working backwards ~

Answer 5

it has to be the one which ends in -20

Answer 6

Or you could do that ^ ;-;

Answer 7

ok thank you guys! i know how to do it now yay(:

Answer 8

so it would have to be D

Answer 9

yes

as the roots are -5, -4 and 1 the factors must be
(x+5)(x+4)(x-1)

and 5 * 4 * -1 = -20

Answer 10

ok got it thanks again!

Answer 11

i deleted the other post because it was wrong...

Answer 12

yw