power rule: To use the power rule, multiply the variable's exponent n, by its coefficient a, then subtract 1 from the exponent. If there's no coefficient (the coefficient is 1), then the exponent will become the new coefficient.
I think, i may be incorrect but the verbal explanation is; -4x is needed to be moved so you add 4x to both sides and 4x cancels out on the left which leaves -2y on the left (when it was moved "x" is always first). then divide all numbers by -2 to get y by itself. this gives you y= -2 - 1/2 if my calculations are correct.