Răspuns:
a) 4
b)29
c)12
d)2
sper ca te-am ajutat
a) 11/8+x/8=15/8
15/8-11/8=4/8
11/8+4/8=15/8
x=4/8
b)y/13+11/13=30/13
30/13-11/13=19/13
19/13+11/13=30/13
y=19/13
c)8/11+n/11+20/11
20/11-8/11=12/11
8/11+12/11=20/11
n=12/11
d)c/15+17/15=19/15
19/15-17/15=2/15
2/15+17/15=19/15
c=2/15
