Question 970657
GROUP THIS

(x^3+2x^2) - (x+2)  NOTE: The negative sign distributes across BOTH the x and the 2.  This is still the same equation.

Factor both terms:

x^2(x+2) - (1) (x+2) ;l I put in the 1 to emphasize it.

The two (x+2) are each multiplied by something, and that is (x^2-1).  I combine them to get (x^2-1) (x+2).

But x^2-1 is a difference of squares, so

(x^2-1) (x+2) becomes (x+1) (x-1)(x+2)