Răspuns:
ex1
a)
7306+1043=8349. 8349-7306=1043
3512+5484=8996. 8996-3512=5484
b)
6009-4533=1476. 1476+4533=6009
7123-1099=6024. 6024+1099=7123
ex2
a)
689+n=7976
n=7976-689
n=7287
5567-2818=5000-n
2749=5000-n
n=5000-2749
n=2251
b)
6001=3450+n
n=6001-3450
n=2551
1012+2918=n-456
3930=n-456
n=3930+456
n=4396
c)
888+n=4678+1067
888+n=5745
n=5745-888
n=4857
n+819=10000-6452
n+819=3548
n=3548-819
n=2729
ex3
a. b. c. a+b. (a+b)-c
2000. 2345. 3876. 4345. 469
1567. 3000. 1672. 4567. 2895
1940. 2627. 999. 4567. 3577