## anonymous one year ago Solve 0=x^3-4x2-7x+28 and tell if it is extraneous

1. anonymous

@sepeario

2. anonymous

Factor by grouping $0=(x^3-4x^2)+(-7x+28)$ Factor the GCF out of each ( ) so that you have the same expression left in both

3. anonymous

So, I got (x^2-7)(x-4)

4. anonymous

yes then set each of those equal to 0 and solve for x

5. anonymous

x=-7,7,4

6. anonymous

the 4 is right $x^2-7=0$ $x^2=7$ $x=\pm \sqrt7$

7. anonymous

Is it extraneous?

8. anonymous

Do you know the meaning of an extraneous solution?