3/4 * 1 1/15 + 1 1/15 * 2 1/2 - 1 3/8 * 1 1/15 = 1 1/15 * (3/4+ 2 1/2 - 1 3/8) = 16/15 * (3/4+ 1/2 - 3/8) = 16/15 * (6/8+ 4/8 - 3/8) =16/15 * 7/8 = 14/15
3/4 * 1 1/15 + 1 1/15 * 2 1/2 - 1 3/8 * 1 1/15 = 1 1/15 * (3/4+ 2 1/2 - 1 3/8) = 16/15 * (3/4+ 1/2 - 3/8) = 16/15 * (6/8+ 4/8 - 3/8) =16/15 * 7/8 = 14/15