It is known that a: B: C = 2:3:4, a + B + C = 27, then the value of a-2b-2c is______ .

It is known that a: B: C = 2:3:4, a + B + C = 27, then the value of a-2b-2c is______ .

Let each share be K, then there is a = 2K, B = 3k, C = 4K. Substituting it into a + B + C = 27, we get 2K + 3K + 4K = 27, the solution is k = 3, that is, a = 6, B = 9, C = 12, then a-2b-2c = 6-18-24 = - 36