1)(5/21+2/21)+2/15=7/21+2/15=1/3+2/15=5/15+2/15=7/15
2)(3/28+1/28)+2/35=4/28+2/35=1/7+2/35=5/35+2/35=7/35=1/5
3)(7/30+1/30)+(8/45+2/45)=8/30+10/45=4/15+10/45=12/45+10/45=22/45
4)(5/24+1/24)+(11/60+13/60)=6/24+24/60=3/12+24/60=15/60+24/60=39/60=13/20
1) -5,2 : (-1 2/5) = - 5 2/10 : (-1 2/5) =
= -52/10 : (-7/5) = 26•5/(5•7) = 26/7 = 3 5/7
2) -1 2/9 : (-5 1/3) = - 11/9 : (-16/3) =
= 11•3/(9•16) = 11/48
3) -4/33 : (-8/55) = 4•55/(33•8) =
= 5/(3•2) = 5/6
4) 8 6/7 : (-31) = 62/7 : (-31) = - 2/7
5) -7 : (-14/17) = 7•17/14 = 17/2 = 8,5
1) целых 45/50+ 5 целых 14/50= 9 целых 59/50= 10 целых 9/50
2)4 целых 3/21+ 14/21+ 1 целая 11/21=5 целых 28/21=6 целых 7/21=6 целых1/3
3)2 целых 6/12+ 3 целых 8/12+ 4 целых9/12= 9 целых 23/12 =10 целых 11/12
4)1 целая 10/30+7/30=1целая 17/30
1) 100 / 5 = 20 (км ) от Минска до Заславля
2) 20 * 2 = 40 (км)