2y 7 5y 9 July 8, 2019 16 32 64 128 3x 2y 7 x 5y =- 9 5x 2y 7 13x 5y 9 4y 7 2y 5y 6 9 3x 5y 4 2y 7 9x 3x 5y 4 2y 7 9x by substitution method 2 5/7y
