6) a-b=277
a:b=5 rest 3
a=5b+3
5b+3-b=277
4b+3=277
4b=274
b=68,5 a=68,5x5+3=345,5
7)a+b+c=86
a:b=3 rest 2
b:c=2 rest 3
a=3b+2; b=2c+3
a=3(2c+3)+2=6c+9+2
a+b+c=6c+11+2c+3+c=9c+14=86
9c=72
c=8; b=19; a=59
8) a:b=c rest 98 restul trebuie sa fie mai mic decat impratitorul, iar b are 2 cifre -> b=99
a=1088=99x10+98
9)a:1002=1000 rest 1001
a=1002x1000+1001=1002000+1001=1003001
