I often have trouble expressing myself when I want to talk about some things (plural) holistically as a single thing.
For example, "differential equations are a form of expression…".
It doesn't seem right to say that somethings (plural) are a something (singular), but I would like to say something like this if it can be done at all correctly.
Best Answer
It is common and acceptable to have a plural noun relating with/to a singular one.
It is common in formal English, and more so in informal English.