=if(A57<"",(A55*A57)*1.095+(C55*A57)*1.1175),Sum( A55:D55))

if you want to add in B55 and D55 in the first case:

=if(A57<"",(A55*A57)*1.095+(C55*A57)*1.1175)+B55+ D55,Sum(A55:D55))


--
Regards,
Tom Ogilvy

"Nick" wrote:

Ok,
This is what i need to do...If a discount is applied in A57 then E55 will
reflect the following: apply the discount to A55 and then tax the new total
by 9.5%tax, apply the discount then to C55 and then tax that new total by
11.75% and then finnally adding the 2 new totals together for a Grand Total,
but if no discount is applied it is a simple formula of A55:D55. Thanks to
whoever can HELP!!!
--
Nick