Question

Given that one zero is -4, find all zeros of P(x)=x^3+x^2-22x-40

Answer 1

factor out the \(x+4\) from your polynomial, then you will have a quadratic, which will probably factor

Answer 2

Wait where are you getting the x+4?

Answer 3

in other words, \[xx^3+x^2-22x-40=(x+4)(\text{ some quadratic})\] you can find the quadratic by
a) long division (ick)
b) synthetic division (very easy) or
c) thinking

Answer 4

if \(-4\) is a zero, then one factor must be \(x+4\)

Answer 5

\[x+4=0\\
x=-4\] so \(x+4\) is a factor for sure

Answer 6

Oh okay

Answer 7

do you know synthetic division?

Answer 8

we can also do it by thinking if you like

Answer 9

or we can cheat
your choice