15 3 x 7 9 July 8, 2019 16 32 64 128 15 3x 3 )- 7 24 13x )=- 98 15 7 9 7 x 2 3 3x 15 x 7 94 3x 15 x 7 90 3 7 x 15 98 9 5 x )= 15 3 7 x 8 9 7 15 x 3 16 7 x 15 chia 3 9 3 x 15