3 5 2 5 x 1 9 2 July 8, 2019 16 32 64 128 2 3 5 х 1 9 26 5 1 2x )+ 3 x 5 )= 2 1 x )- 9 1 3 2 5 x 8 9 2 3 5 6 5 3/5 x 1 4/21