how do you unfoil 3xsquared+5x-2=0?

Answer 1

Rearrange equation into:
3x²-x + 6x-2
=x(3x-1) + 2(3x-1)
=(x+2)(3x-1)

or use the quadratic formula,
or by completing squares.

Answer 2

how did you get the 6x?

Answer 3

5x = -x + 6x