Răspuns :
a + b = 81
a= b : 2 => b = 2 x a
a + 2a = 81
3a= 81
a= 81 : 3
a = 27
b = 27 x 2 => 54
v: 27 + 54 = 81
a= b : 2 => b = 2 x a
a + 2a = 81
3a= 81
a= 81 : 3
a = 27
b = 27 x 2 => 54
v: 27 + 54 = 81