If x and y are opposite to each other, then x + 2y-4 = 0=______ ,y=______ .

If x and y are opposite to each other, then x + 2y-4 = 0=______ ,y=______ .

From X and y are opposite numbers, we can get x + y = 0, that is, x = - Y. substituting it into the known equation, we can get: - y + 2y-4 = 0, and the solution is y = 4, x = - 4, so the answer is: - 4; 4