4x 9 2x =- 5x 12 July 8, 2019 16 32 64 128 2x 9 )( 4x 2 5x 12 5x 9 2x 6 5 5x 12 4x 4x 9 2x 5 8x 16 5x 12 4x-12 + 5x-15 9x-9 4x + 9 - 15 2-x =5