X 3y 3 3x 9y 2 July 8, 2019 16 32 64 128 X 3y 3 3x 9y 2 by substitution method X 3y 3 3x 9y 2 by elimination method X 3y 3 0 3x 9y 2 0 by elimination method X 3y 3 0 3x 9y 2 0 X 3y 3 0 3x 9y 2 0 by cross multiplication method 1 x 3y 3 0 3x 9y 2 0