1)(5/6-3/7)*42=17
1. 5/6-3/7=35-18/42=17/42
2. 17/42*42=17*42/42(сокращаем)=17
2)(14/15-3/5)*15=5
1. 14/15-3/5=14-9/15=5/15=1/3
2. 1/3*15=1*15/3(сокращаем)=5
3)18(8/9-5/18)=11
1. 8/9-5/18=16-5/18=11/18
2. 18*11/18=18*11/18(сокращаем)=11
1)(5/6-3/7)*42=17
1. 5/6-3/7=35-18/42=17/42
2. 17/42*42=17*42/42(сокращаем)=17
2)(14/15-3/5)*15=5
1. 14/15-3/5=14-9/15=5/15=1/3
2. 1/3*15=1*15/3(сокращаем)=5
3)18(8/9-5/18)=11
1. 8/9-5/18=16-5/18=11/18
2. 18*11/18=18*11/18(сокращаем)=11