Answer:
[tex]\boxed{\bold{d - r + c}}[/tex]
Step-by-step explanation:
x - c = d - r
You want to get x by itself
c is with x so get rid of c
Opposite of -c is +3, so add c to both sides
x - c + c = d - r + c
-c + c cancel each other out so now you have x by itself
x = d - r + c