Answer: All Real Numbers
Explanation: Notice that when you try to put your variables together on one side of the equation by subtracting 4y from both sides, the y terms cancel out on both sides and we no longer have a variable in the equation.
Notice however that we are left with the statement 12 = 12.
Since 12 = 12 is a true statement, we say that
the solution to this equation is all real numbers.