Question

How do i solve this?

x^3+x^2-4x-4=0

Answer 1

x^3+x^2-4x-4=0


(x^3+x^2)+(-4x-4)=0


x^2(x+1)+(-4x-4)=0


x^2(x+1)-4(x+1)=0


(x^2-4)(x+1)=0


(x-2)(x+2)(x+1)=0


x-2=0, x+2=0, or x+1=0


x=2, x=-2, or x=-1

Answer 2

On the third step, why do you put x^2(x+1) ?

Answer 3

I factored out x^2 from x^3+x^2

Answer 4

I did this so I could get two copies of x+1 (afterwards I factored -4 from -4x-4 to get another copy of x+1)

Answer 5

Does that make sense?

Answer 6

Not really. Solving equations, has always been the hardest for me.

Answer 7

well going from x^3+x^2-4x-4=0 to (x-2)(x+2)(x+1)=0, I'm factoring the left side


once everything is factored, I then use the zero product property to solve for x.

Answer 8

Cant you use the distance formula?

Answer 9

the distance formula won't work too well in this setting, so I'm not sure why you're thinking of that (unless this is for another problem?)