4,61+(2,29)= -3,08+1,69= 3/10+(-4/5)= -1/20+1/30= 5/8+(-1)= 2 3/4+(-9 5/6)=

4,61+2,29=6,9
-(3,08-1,69)=-1,39

3/10-4/5= 3/10 - 8/10 = -5/10 =-1/2

-1/20+1/30= -(1/20-1/30)= -( 3/60 - 2/60 ) = -1/60

5/8-1= 5/8- 8/8= -3/8

2 3/4- 9 5/6 = - (9 5/6 - 2 3/4) = -( 9 10/12 - 2 9/12) = - 7 1/12