Efectuati:
decat a,b,c,e

a)=5/2-(+5/4)-14/9(simplifici prima fractie cu 2)= 10/4-5/4-14/9=5/4-14/9= 45/36-70/36=-25/36
b)=7/3+1/6(amplifica prima reacție cu 2)=14/6-1/6=13/6
c)=3/12+10/12+4/12=17/12
e)=9/4-5+11/4=9/4-20/4+11/4= -11/4+11/4=0