1) 3 9/23 · 23/27 = 78/23 · 23/27 = 78/27 = 26/9 = 2 8/9
2) 1 1/45 · 1/6 = 46/45 · 1/6 = (23·1)/(45·3) = 23/135
3) 14 7/15 - 2 8/9 = 14 21/45 - 2 40/45 = 13 66/45 - 2 40/45 = 11 26/45
4) 11 26/45 - 23/135 = 11 78/135 - 23/135 = 11 55/135 = 11 11/27
