It does not matter whether or not you have a d or a c to use for an unknown number, because you do not know what that number is. The letter does not abbreviate something, it's just a symbol to fill in the place of the missing number.
Ok so let's start with the definition of variables: variables mean something that gets put in if u don't know the answer it could be a letter number a shape. Does not matter it is something filling in for that missing answer. It is a lot times used in algebra questions you need to find the answer to.
Ok now let's answer your question we'll it does not matter because we'll it is basically just something filling in for a unknown number. So you can figure out it. It does not matter if it is a square d a or 1 just it is filling in for a unknown number.
See what I mean thank you hope I helped - from nerdalerted
