Question

Simplify a - {b - [c - (d - e) - f] - g}.

Answer 1

a - {b - [c - (d - e) - f] - g}
remove the parentheses from the inside out
=a - {b - [c - d + e - f] - g}
= a - {b - c + d - e + f - g}
= a - b + c - d + e - f + g

Answer 2

-(a + b)
= -a - b

effectively you are distributing -1 over the contents of the brackets

Answer 3

-(a + b)
= -1(a + b)
= -1*a -1*+b
= -a - b