What polynomial has roots of −5, −4, and 1

Question

asked Sep 5, 2019 79.5k views

2 Answers

Ball · Answer 1 · 2019-09-11T15:48:45+0000

Answer:

D

Explanation:

The question continues with these options:

a. x3 − 8x2 − 11x + 20

b. x3 − x2 + 22x + 40

c. x3 + x2 − 22x − 40

d. x3 + 8x2 + 11x − 20

A cubic in equation (x+5)(x+4)(x-1) or on a graph that crosses at -5, -4, and 1. Multiply the factors out to find the equation.

(x+5)(x+4) = x^2+5x+4x+20=x^2+9x+20

$(x-1)(x^2+9x+20)\\x^3-x^2+9x^2-9x+20x-20\\x^3+8x^2+11x-20$