Rút gọn: C=(a+2b−3c)−2(a−b+c)+3(b+c)

Rút gọn:

C=(a+2b−3c)−2(a−b+c)+3(b+c)C = (a + 2b - 3c) - 2(a - b + c) + 3(b + c)C=(a+2b−3c)−2(a−b+c)+3(b+c)