Formula that is KILLING MY TINY BRAIN

Hi guys, new to this. New to Excel actually so this may be quite trivial to the majority of you.

I've been attempting this formula for the past 2 hours and I am well and truly stumped.
Im finding it hard to describe exactly what I'm trying to do but here goes:

This is the formula I have finally come up with but to no avail

=Cell 1-(Cell2*Cell3)/Cell4

So I want the out come of Cell 5 to be the total of Cell 2 multiplied by Cell 3, the total of that subtracted off Cell 1 then divided by Cell 4.

I may well be over complicating things and can attempt to explain further if necessary?

Thanks a lot