7x - 2y = 15 July 8, 2019 16 32 64 128 7x 2y 15 7x 2y 15 2x y 9 7x 2y 15 in slope intercept form 7x 2y 15 y 6 2x 7x 2y 3z 15 7x 2y 1 3x 4y 15 7x 2y 5 8x 7y 15 7x 2y 1 3x 4y 15 by substitution method