-5/12-3/4=-7/6;
-7/6:2(1/3)=-7/6:7/3=7/6*3/7=1/2;
5(1/3)*0.75=16/3*3/4=4;
4+1/2=4(1/2);
2) -2,5-1(5/6)=2(1/2)-1(5/6)=-5/2-11/6=26/6;
26/6/:13/9=26/6*9/13=3;
3-3(5/9)=-5/9;
-5/9*-2(1/4)=-5/9*-9/1=5;
3) -3,8+2(1/3)=-3(4/5)+2(1/3)=-19/5-7/3=-22/15;
-22/15*-1(7/8)=22/15*15/8=11/4;
25/6:-5/3=25/6*=3/5=-5/2;
11/4+(-5/2)=1/4;