9 2x 3y 8 0 x 4y 7 0 July 8, 2019 16 32 64 128 6xy - 4y + 6 - 9x 4) 8x - 9y - 21 = 0 3x - 2y - 12 = 0 2) 9x - (7y - 4x) 4) 8x - (3y + 5x) - (- 2y - x)