1)d:i=9 rest3 d=9i+3
D+i+c+r=115
9i+3+i+9+3=115
10i+15=115
10i=115-15
10i=100
I=100:10
I=10
D:10=9 rest 3
D=9x10+3
D=90+3
D=93
Verificare :93:10=9 rest 3
90
=3
10+93+9+3=115
2)a+b+c=3305
A=3b
c=a+15
3b+b+3b+15=3305
7b=3305-15
B=3290:7
B=470
A=3x470=1410
C=1410+15=1425
Verificare :1410+470+1425=3305
3)a=975:5=195
975-c=420
C=975-420
C=555
A+b+c=195+975+555=1725