Question

Find the zeros of the function. f(x) = 9x^3 + 36x^2 + 27x

Answer 1

9x^3 + 36x^2 + 27x=0
 9x(x^2 + 4x + 3)=0
9x(x+3)(x+1)=0
9x=0; x=0
x+3=0; x=-3
x+1=0; x=-1
answer
x=0; x=-1; x=-3

Answer 2

We can take out x so x = 0  is one of the zeroes.

In fact the GCF is 9x so:-

9x(x^2 + 4x + 3) = 0
x^2 + 4x + 3 = 0
( x + 3)(x + 1) = 0
giving x = -1 or -3

The three zeroes are 0 , -1 and -3.