Can I perform a calculation in Calc and enter the calculation result in the cells of the Writer document in the form of mathematical formulas so that when the calculations in Calc are changed, they will change in Writer in the written formulas in mathematical form?
Your question is related to the spreadsheet app Calc, not to the formula editor Math. Please retag to replace math with calc. Press Enter twice to exit retag mode.
“Cells of the Writer document” can only occur in a TextTable. TextTable objects are a mess. I cannot see, e.g, a reasonable way for a helping spreadsheet document to refer to cell contents of such an object.
In addition I cannot understand the “so that when the calculations in Calc are changed, they will change in Writer in the written formulas in mathematical form”. What are “changed calculations”? What are “written formulas in mathematical form” in Writer?
What you can do to get spreadsheet functionality inside a Writer document: Insert a Calc document as an OLE object.
(Please also regard the comment by @ajlittoz.)