which of the following correctly shows the first step when factoring x^3+2x^2-4x-8 by grouping
x(x+2)+4(x-2)
x^2(x^2+2)+4(x-2)
x^2(x+2)-4(x+2)
x(x^2+2)-4(x+2)
None of the choices show the correct first step for factoring x^3+2x^2-4x-8 by grouping.
The correct first step in factoring x^3+2x^2-4x-8 by grouping is to group the first two terms together and the last two terms together:
x^3 + 2x^2 - 4x - 8
= (x^3 + 2x^2) + (-4x - 8)
Then, factor out the common terms in each pair:
= x^2(x + 2) - 4(x + 2)
Therefore, the correct first step is x^2(x + 2) - 4(x + 2).