Question

-a-la + {a + b - 2a - (a - 2b)} - b] ​

Answer 1

Given,
−a−[a+{a+b−2a−(a−2b)}−b]

=−a−[a+{a+b−2a−a+2b}−b]

=−a−[a+{−2a+3b}−b]

=−a−[a−2a+3b−b]

=−a−[−a+2b]

=−a+a−2b

=−2b