How to fill a formula with functions and plain text or uninterpreted characters?

I saw this page on the wiki but i don’t seem to understand this at all.

Say that I have values in cells C1 and C2, that are the result of functions. Let’s say that their respective values are 50 and 60. Now, I want cell C3 to show:

(50 - 60)

How do I do that? I tried using

=(C1 "-" C2)

But I get an Err:509
I think I tried all combinations, with either {}{} or “” around every single character (dash, brackets…) and even the VALUE() function for each cell name…

Any idea?

I guess it is the same as asking how to integrate a cell value in a sentence, say I want to have in a cell something like “I have a value of [cell C1] for this”.


The question is, of course, relevant, and always fresh for us the ignorant, Mr. Kemp.
Google results for “libreoffice formula and text” took me here.
insert =C1&" “&”-"&" "&C2

Thank you, @hoja420 ! We can even do simpler: =C1&" - "&C2