Solve these 2 exercises . a + (a-b) + (- a + b) a²+[-b²+2a²]-[a²-b²]

First remember that:
- × - = +
+ × + = +
- × + = -
+ × - = -
and:


a+ (a-b) + (-a+b)=
a + a -b -a+b= a



please mark as brainliest answer.

Uneed to add them up 27+18+23=68