3ab3:ab=87
suy ra: (3000+a00+b00+3):ab=87
suy ra: (3003+ab0):ab=87
suy ra: 3003:ab+ab0:ab=87
suy ra: 3003:ab+10=87
suy ra: 3003:ab=77
suy ra: ab=3003:77
suy ra: ab=39
3ab3 = ab x 87
3003 + ab x 10 = ab x 87
ab x 77 = 3003
ab = 39
So can tim la 39
3ab3 = ab x 87
3003 + ab x 10 = ab x 87
ab x 77 = 3003
ab = 39
So can tim la 39