Try this, then:

=SUM(IF((A1:A10="ABC")*(B1:B10="DEF"),C1:C10,0))*D 1

This is an array formula, which means that once you have typed it in
(or subsequently edit it) then instead of using just <ENTER you must
use CTRL-SHIFT-ENTER together. If you do this correctly then Excel will
wrap curly braces { } around the formula - you must not type these
yourself.

I'm not sure if you want one composite formula in your second part of
the posting, or three similar formulae.

Hope this helps.

Pete