1) =-0,07 - 1,23= - 1,3
2) =5,64 - 12,8= - (12,8-5,64)= - 7,16
3) = - 2,19+7,06=7,06-2,19=4,87
4) = - 7,1+9,7=9,7-7,1=2,6
5) = - 1,4-0,5= - (1,4+0,5)= - 1,9
6) = 1/6-1/4=2/12-3/12=1/12
7) = - 1 1/2-5/6= - (1 3/6+5/6)= - 1 8/6= - 2 1/3
8) = 3/4-1/8=6/8-1/8=5/8
9) =2 1/9 - 3 2/3= - (3 6/9 - 2 1/9)= - 5/9
10) = -4 - 1 1/7= - (4+1 1/7)= - 5 1/7
11) =2 7/12-4/9=2 21/36 - 16/36=2 5/36
12) = 5/8-7/24=15/24-7/24=8/24=1/3
13) = 8 23/40 - 7 5/8=8 23/40 - 7 25/40=38/40=19/20
14) = -(4 2/9+2 1/6)= - (4 4/18+2 3/18)= - 6 7/18
15) =8-6 3/7=7 7/7-6 3/7=1 4/7
16) = -(7 3/5 - 2 1/3)= - (7 9/15 - 2 5/15)= - 5 4/15
17) = - (6 3/5+13 4/5)= - 20 2/5
18) =- (10,3+2,5)= - 12,8
19) =2,6-0,75=1,85
20) = -(1,5+0,26)= - 1,76
21) =2,05-3,4= - 1,35
22) = -(3/4+5/6)= - (9/12+10/12)= - 1 7/12
23) = 2,81 -1,3=1,51
24) = 4/15 - 2/5=4/15 - 6/15= - 2/15
25) = 20,6-15,8=4,8
26) = - (1 14/18+3 15/18)= - 4 29/18= - 5 11/18
27) = 3 80/90 -3 81/90= - 1/90
28) = - 5 63/72+5 64/72= 1/72
29) = -2 25/30+2 24/30= - 1/30
30) =0