Răspuns :
a - b = 50
a : b = 3 rest 10
a = 3b + 10
3b + 10 - b = 50
2b = 50 - 10
b = 40 : 2
b = 20
a = 3 * 20 + 10
a = 70
a : b = 3 rest 10
a = 3b + 10
3b + 10 - b = 50
2b = 50 - 10
b = 40 : 2
b = 20
a = 3 * 20 + 10
a = 70