first we multiply both sides by 3, so we get 42=4y-6x, because the division and multiplication cancel each other out, then we move the variable to the other side, so we subtract 4 on both sides and cancel out 4y-4y, so we and up with -4y=-6x-42, then we can divide both sides by -4, so:
final answer: y=3/2x + 21/2