7 1 4 x 9 1 2 July 8, 2019 16 32 64 128 4 x − 1 2 1 3 7 9 7 1 − x 4 1 2x 9 7 1/2 x 4 7 1/2 x 9 7 1/2 x 4 1/2 9/7 x 4
