Răspuns:
3111+a-10 000=100
3111+a=10000-100
3111+a=9900
a=9900-3111
a=6789
5000-b+500=2000
5000-b=2000-500
5000-b=1500
b=5000-1500
b=3500
180+c+17070=30000
180+c=30000-17070
c=12930-180
c=12750
9000-d-3333=2000
9000-d=2000+3333
d=9000-5333
d=3667
20000-e+150-9100=1050
20000-e=1050+9100-150
e=20000-10000
e=10000
