Answer
$(x+2)(3x-4)$
Work Step by Step
First, for the polynomial $3x^2 + 2x - 8$, we write
$$
3x^2 + 2x - 8=3x^2 + 6x -4x- 8
.$$
By grouping the first two terms and the second two terms and then taking common factors, we have
$$
3x^2 + 6x -4x- 8=3x(x+2)-4(x+2)=(x+2)(3x-4)
.$$