Respuesta :

Q21)Answer: 4c - 1
2c + (c - 6) + (c + 5)
= 2c + c - 6 + c + 5
= 4c - 1

Q22) Answer: 15f + 7
(6f - 3) + (5f + 14) + [4(f - 1)]
= 6f - 3 + 5f + 14 + (4f - 4)
= 6f - 3 + 5f + 14 + 4f - 4
= 15f + 7