x = +/- sqrt(y/3)
Yes. (Assuming that -3x2 is the best representation of 3x2 that this browser will allow.)
The coefficient is -3.
They are multiplicands.
3x2 - 10x - 8 = (3x + 2) (x - 4)
3x2 + 17x + c = 0, rearranging gives c = -3x2 - 17x
In general, no.