4,2-(5,2-3,8)=
-7,2+(3,8-2,9)=
9,3-(-2,8+3,1)=
-(1,8-1,4)-1,2=
4,7-(2,7-1,14)=
1,16-(3,8-1,2)=
0,2+(a-0,1)=
(t+4)-7=
-(3-a)+4=
-2-(t-1)=
(x-1)-(y+2)=
-(a-2)+(c+3)=

4,2-(5,2-3,8)=2,8-7,2+(3,8-2,9)=-6,39,3-(-2,8+3,1)=9-(1,8-1,4)-1,2=-1,64,7-(2,7-1,14)=3,141,16-(3,8-1,2)=-1,440,2+(a-0,1)=0,2+a-0,1=0,1+a  (t+4)-7=t+4-7=t-3 t=3-(3-a)+4=-3+a+4=1+a -2-(t-1)=-2-t+1=-t-1  (x-1)-(y+2)=x-1-y-2=x-y-3-(a-2)+(c+3)=-a+2+c+3=a+c+5