Răspuns :
a-b=630
a:b=4 rest 9
a=4b+9
ab+9-b=630
3b=630-9
3b=621
b=621:3
b=207
a-207=630
a=630+207
a=837
837-207=630
a:b=4 rest 9
a=4b+9
ab+9-b=630
3b=630-9
3b=621
b=621:3
b=207
a-207=630
a=630+207
a=837
837-207=630