4y + 3 - 10y - 11 = 7 + 13 - 4y; 4y - 10y + 4y = 7 + 13 + 11 - 3; y(4 - 10 + 4) = 28; -10y = 28; y = 28 : (-10); y = -2.8.
4y + 3 - 10y - 11 = 7 + 13 - 4y; 4y - 10y + 4y = 7 + 13 + 11 - 3; y(4 - 10 + 4) = 28; -10y = 28; y = 28 : (-10); y = -2.8.