And please ditch the unnecessary use of the SUM function.

=(A1*B1+C1*D1)*0.80 will do, or, if you want to make it clearer where you
got the 0.8,
=(A1*B1+C1*D1)*(1-20%)
--
David Biddulph

"Sheeloo" <="to" & CHAR(95) & "sheeloo" & CHAR(64) & "hotmail.com" wrote in
message ...
When you subtract 20% from a number then you are left with 80% so multiply
by
0.8

=Sum(A1*B1+C1*D1)*0.80

Will give you 80% of AB + CD

"Denise B" wrote:

Formula:
=sum(A*B+C*D) then I want to subtract 20%. I have tried several ways and
cannot get it right.