Presumably your class should have covered the process of pivoting
http://mathworld.wolfram.com/Pivoting.html
to deal with this situation. Reordering rows is equivalent to
pre-multiplying by by a matrix that has only one 1 in each row/column,
with the rest zero.

Jerry

cjrrussell wrote:

For an assignment i am doing at uni i have been asked to produce a
spreadsheet that will solve a set of 5 simultaneous equations using
gaussian elimination.

I have set up the spreadsheet to do this, however, we have also been
asked to make it work if we get a zero on the leading diagonal. This
means that the equations would have to be rearranged.

This is the part im not sure how to do. Obviously i would be starting
with an 'IF' expression, but other than that i dont know where to
start.

Hopefully someone will be able to help me

Thanks in advance

Chris