Question

a+(-b)-(-2a)

-a-(+a)+2b - (-b)

-a-(-b)-4a

-a-(+3a)+(-b)-b

Answer 1

A+(-b)-(-2a) =а-b+2a=3a-b

-a-(+a)+2b - (-b)=-a-a+2b+b=-2a+3b

-a-(-b)-4a=-a+b-4a=b-5a

-a-(+3a)+(-b)-b= -a-3a-b-b=-4a-2b