X y 2 4 xy 1 3 July 8, 2019 16 32 64 128 X y 2 xy 4 x 3 y 5 1 3 x y 2 xy 2 9 x y 4 xy 1 X y 2 xy 4 và x 3 y 5 1 3 x y 2 xy 2 9 x y 4 xy 1 by elimination method 5 x y 2 xy 3 15 x y 4 xy 1 If x 2 y 3 4 1 then xy
