Question

здрастеееее решите пжлссстттт​

Answer 1

a + 2b = 3

b + 2c = 4

c + 2a = 5

a + 2b + b + 2c + c + 2a = 3 + 4 + 5

3a + 3b + 3c = 12

3(a + b + c) = 12

a + b + c = 4