Algebra help
posted by Claure on .
f(x)=x^34x^2x+4
How do I find the xintercept for this?
This is from my book:
step 1: 0=x^34x^2x+4
step 2: 0=x^2(x4)+(1)(x4)
step 3: 0=(x^21)(x4)
I know how to solve once I get to step 3, but in step 2, I don't know what they've done or why. Where does that (1) come from? Why is it (x4)?
Please help explain this to me. I'd be really thankful.

step 1: 0=x^34x^2x+4
we would like to factor that.
rewrite as
x^34x^2  (x4)
now you can see that I can factor an (x4) out of the first two terms
x^2 (x4)  (x4)
which is
x^2 (x4) 1 (x4)
step 2: 0=x^2(x4)+(1)(x4)
step 3: 0=(x^21)(x4)