Question

b-(c-d)
b+(-c-d)
(a-b)+(-c+d)
-(a-b)+(c-d)
-(a+b)-(c+d)
5-(3+x)
-x+(x+2,7)
-2+(3,1-x)

Answer 1

b-c+d
b-c-d
a-b-c+d
-a+b+c-d
-a-b-c-d
5-3-x=2-x
-x+x+2,7=2,7
-2+3,1-x=1,1-x