Решите 1)5/6 - 3/4= 2)13/21 + 1/2= 3)(3/4 - 1/6) + (7/8 - 5/6)= 4)(7/9 - 13/18) + (7/9 - 2/3)= 5)1-26/43 + 1/2=

1) 5/6-3/4= 10/12-9/12=1/12
2) 13/21+1/2=26/42+21/42=47/42=1 целая 5/42
3)(3/4-1/6)+(7/8-5/6)=(9/12-2/12)+(21/24-20/24)=7/12+1/24=14/24+1/24=15/24=5/8
4)(7/9-13/18)+(7/9-2/3)=(14/18-13/18)+(7/9-6/9)=1/18+1/9=1/18+2/18=3/18=1/6
5)1-26/43+1/2=43/43-26/43=17/43+1/2=34/86+43/86=77/86