Răspuns:
Ex.5
a.=1/5-1/5=0
b.=-7/3+5/3=-2/3
c.=11/4+1/4=12/4=3
d.1/3+4/3=5/3
e.-2/5+7/5=5/5=1
f.4/3+1/3=5/3
ex.6
a.2/3-7/5+1/15=-10/15=-2/3
b.-1/7-3/14+1/2=2/14=1/7
c.5/8-1/2-3/4=-5/8
Explicație pas cu pas: