(3/4-4/5)*7,8+(2/3+4/7)*7/13=??

Question

(3/4-4/5)*7,8+(2/3+4/7)*7/13=??

Answer 1

1)3/4-4/5=15/20-16/20=-1/20
2)2/3+4/7=14/21+12/21=26/21=1 5/21
3)-1/2*7,8=-1/2*7 4/5=-39/10=-3 9/10
4)1 5/21*7/13=26/21*7/13=2/3
5)-3 9/10+2/3=-3910+2/3=-117/30+20/30=-97/30=-3 7/30