Question

A = x - 6
B = 2x + 3
C = 1 - 2x

(A + 2B) + (2A - C) - (C + B)

Answer 1

*) (A+2B) = ( (x - 6) - 2(2x + 3) ) = -3x - 12

*) (2A-C) = ( 2(x - 6) - (1 - 2x) ) = 4x - 7

*) (C+B) = ( (1-2x) + (2x + 3) ) = 4

Jadi,
(A+2B) + (2A-C) - (C+B)
= (-3x - 12) + (4x-7) - (4)
= x - 23