2 4x 7 )= 7x 9 July 8, 2019 16 32 64 128 7x 2 4x 7 9x 7 5x 2 4x 7 7x 2 90 (- 4x 2 11x 7 )-( 5x 2 7x 9 4x 2 2x 7 3x 7x 2 9 2 7x 9 11x 4x 7 2x 7 2 7(x-4 7)=9 45
