If you delete the cell upon which the formula is based,

not the cell with the formula in it, then the cell with the formula in it should go blank.

For example:
Cell A10 contains the formula =Sum(A1 + A2)
Cell A1 contains 5
Cell A2 contains 2

Now cell A10 contains 7

Delete the contents of A1 and A2 and Cell A10 is now blank

That work for you

P