1) (3 1/12+7/12)-4 3/12=(37/12+7/12)-51/12=-7/12
2) (10 1/11*2)-10/11=(111/11*2)-10/11=212/11
3) 20,41*0,3+101,25=6,123+101,25=107,373
4) 3,15-(x+1,1)=0
3,15-x-1,1=0
2,05-x=0
-x=-2,05
x=2,05
5) (310,75/1,5-10,75)*0,05=(207,16-10,75)*0,05=196,41*0,05=9,8205