Answer:
3a - b - c
Step-by-step explanation:
a - 2b - (c-(2a+b))
a - 2b - c + (2a+b)
a-1[2b+{c-2a-b}]
or, a-1[2b+c-2a-b]
or, a-2b-c+2a+b
or, 3a-b+c
