Question

Solve 0=x^3-4x2-7x+28 and tell if it is extraneous

Answer 1

@sepeario

Answer 2

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

Answer 3

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

Answer 4

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

Answer 5

x=-7,7,4

Answer 6

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

Answer 7

Is it extraneous?

Answer 8

Do you know the meaning of an extraneous solution?