a)
1)26/15+1/10-4/3=amplificând 26/15 cu 20 primim =520/300,amplificând 1/10 cu 30 primim=30/300,amplificand 4/3 cu 100 primim =400/300.
520/300+30/300-400/300=150/300,simplificam cu 150=1/2
2)1/2-1/2=0
3)0×3/11=0
4)1/2-0=1/2
5)1/2+1/2=2/2=1/1=1.
