Răspuns :
a-b=308
a:b=3 rest 50 => a= 3b+50
3b+50-b=308
2b=308-50
2b=258
b=258:2
b=129
a=129×3+50
a=387+50
a=437
a - b = 308
a : b = 3 rest 50
a = 3 × b + 50
3 × b + 50 - b = 308
2 × b + 50 = 308
2 × b = 308 - 50
2 × b = 258
b = 258 : 2
b = 129
a = 3 × 129 + 50
a = 387 + 50
a = 437