Question

What polynomial has roots of -4, 2, and 5 ?

x3 - x2 - 22x + 40
x3 + x2 - 22x - 40
x3 + 3x2 - 18x - 40
x3 - 3x2 - 18x + 40

Answer 1

x=-4 -> x+4=0
x=2 -> x-2=0
x=5 -> x-5=0
(x+4)(x-2)(x-5) is the polynomial
\[x^3-3x^2−18^x+40\]
is the answer.

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Another solution:
plug in -4, 2, 5 in every equation. The one that you get 0 for all three is the correct answer.

Answer 2

Correction:

\[x^3−3x^2−18x+40\]

Answer 3

thank you bunches