# How to explain a mathematical process?

Consider we have two expressions A, and B.

If we have C = A + B, we can say (I have seen this multiple times in academic papers):

C can be written as a sum of two expressions.

Now the question is, what can we say if we have:

C = A - B

Please, note that I am looking for a very technical word. for example, we cannot use the words "addition" , "plus" in the first sentence. I have never seen such sentences with these synonyms. Thanks

More Details:

• "C can be written as a difference of two expressions."? I'm not savvy in math terminology, I've just looked up my Russo-English dictionary. I also use the word term for literals like A, B, C, etc. Commented Dec 2, 2015 at 18:15
• This question is a part of what was asked in "How do you read these mathematical expressions aloud?".This question is specifically asking for a formal written phrasing, whereas that question was asking how an expression would be "read aloud". Commented Dec 2, 2015 at 18:20
• I think "the" is somewhat preferred to "a" here. Can be written as the difference of two equations, or the quotient of two equations, and so on. It's not that "a" is at all incorrect, it just feels like "the" has a little more importance to it. Commented Dec 2, 2015 at 18:23
• @CopperKettle the google results: "can be written as a sum of two terms" : 113000 "can be written as a difference of two terms" : 3 results Commented Dec 2, 2015 at 18:24
• As an engineer, I think any A-B can be written as A+(-B). I think that is the reason why such a sentence is rare. However, I curious to know about it Commented Dec 2, 2015 at 18:26

The comment above is correct. What you are describing is the "difference". Likewise, C= A*B is the "product" of two expressions and C= A/B is the "quotient".

Hope this helps!