help pls am nevoie rauuu

Explicație pas cu pas:
a) 2/10 +6/10
1/10+7/10
3/10+5/10
7/10+1/10
5/10+3/10
b) 1/10+3/10+4/10
3/10+4/10+1/10
2/10+3/10+3/10
4/10+1/10+3/10
c) 4/10+4/10