Respuesta :
a - {5b - [a - (3b - 2c) + c - (a - 2b - c)]}
= a - 5b - a - 3b + 2c + c - a + 2b + c
= -a - 6b + 4c
answer is -a - 6b + 4c (first choice)
= a - 5b - a - 3b + 2c + c - a + 2b + c
= -a - 6b + 4c
answer is -a - 6b + 4c (first choice)