Is there a formula in Google Sheets that can preform an equation only if certain conditions are met?

Question

In Google Sheets I have a column (column M) which has values of either "-" or a number. I'm trying to figure out if there is a way to make a formula that would divide column M by column N only if the value in column M isn't a "-"

I tried several variations on the formula below but could not make it work.

=IF(M2="-","-",(=M2/N2))

Answer 1

=IF(M2="-",,M2/N2)

Or, for the whole column at once, assuming no blank cells in column M:

=ARRAYFORMULA(IF(M2:M="-",,M2:M/N2:N))