I'm not sure what your precise formula  is, as there is a "2" at the end of
it and another "2" in a line by itself. Can I assume that those "2"s
shouldn't be there?

If so, this sounds like homework and like simple Algebra not Excel.
Therefore I won't supply the answer directly.

However, the formula appears to be a simple multiplication. To get the
result of a multiplication to be zero, then either or both sides of the
multiplication symbol must equal zero. You've said that B29 is not zero, so
... over to you.