Пошаговое объяснение:
1) 3 3/11:18=36/11*1/18=2/11
100:25/36=100*36/25=144
5 1/6:1 1/30=31/6*30/31=5
2/11+144=144 2/11
144 2/11-5=139 2/11
2) 12 3/5:21/25=63/5*25/21=15
17/20:1.19=17/20*100/119=5/7
3 1/17:1 1/51=52/17*51/52=3
15-5/7=14 2/7
14 2/7+3=17 2/7
