Răspuns:
a+159=400
a=400-159
a=241
942-b=400
b=942-400
b=542
c×20=400
c=400:20
c=20
h-399=400
h=400+399
h=799
800:x=400
x=800:400
x=2
1 11 6
9 4 5
8 3 7
