2 7 1 9=2x 1 5 July 8, 2019 16 32 64 128 7 2x 1 2x 5 1 2 9 2x 2 7+1 9=2x+1 5 2 7-(5 9-1 2)= 2 7 - 1 9 2 7 / 2 9-1 1
