X 6 y 4 x 5 y 7 July 8, 2019 16 32 64 128 5 x 6 y 13 3 x 4 y 7 X/3=y 4 y/5=z/6 và x+z=78 Solve x 3 y 4 11 5 x 6 y 3 =- 7 3 x 4 y 5 and 6 x 8 y 7
