3+c - (4+c)
pretend that there is a -1 in front of the bracket
3+c-1(4+c)
multiply the bracket by -1
(-1)(4)=-4
(-1)(c)=-c
3+c-4-c
3-4+c-c ( combine like terms)
+c-c=0
3-4=-1
-1+0=-1
Answer:
-1
