Question

-(a+b)+[-4a+5b-{-3a+2b-(3a-5b)}+4a]

Answer 1

-(a+b)+[-4a+5b-{-3a+2b-3a-5b}+4a]
-(a+b)+[-4a+5b-{-6a-3b}+4a]
-(a+b)+[-4a+5b+6a+3b+4a]
-(a+b)+[6a+8b]
-a-b+6a+8b
5a+7b