a) -1,1(6)=(-1)(116-11)/90=(-1)(105)/90=simplif cu 15=-7/6
-1,75=-175/100=simplif cu 25=-7/4
0,(3)=3/9 simplif cu 3=1/3
-0,(5)=-5/9
-7/6:(-7/4)+1/3-(-5/9)=
(-7/6)·(-4/7)+1/3+5/9=
2/3+1/3+5/9=
3/3+5/9=1+5/9=(9+5)/9=14/9=1,(5)
b) =33/15·[2-4/5·(10-9)/18]=
=11/5·[2-4/5·1/18]=
=11/5·(2-2/45)=
11/5·(90-2)/45=
=11/5·88/45=968/225=4,30(2)