Răspuns :
a + b = 53
a = 4b + 3
4b + 3 + b = 53
5b = 53 - 3
5b = 50
b = 50 : 5
b = 10
a = 53 - 10
a = 43
a = 4b + 3
4b + 3 + b = 53
5b = 53 - 3
5b = 50
b = 50 : 5
b = 10
a = 53 - 10
a = 43