X^3 + 9x^2 + 20x = 0?

Question

I don't know what do do because the equation isn't in the form of x^4 9x^2

Please help me!!

Answer 1

x^3+9x^2+20x=0

x(x^2+9x+20)=0

x(x+5)(x+4)=0

For these three terms to multiply out to give 0, at least one of them

must have a value of 0

So x=0, (x+5)=0, or (x+4)=0

Thus x=0, x= -5, or x= -4