Simplifying a long formula with the Sum of the Product (in each row).

What I am trying to do is actually very simple, even because I've already found a way to do it, although it is too long and takes to much work to do. maybe you guys can figure out a simpler way to do it.

1. The result cells are supposed to be the sum of the product of two cells.
2. The long formula I made to get what I wanted was:

Please Login or Register  to view this content.

*As you can see, I made it from bottom to top, sorry.

3. I have to do the same thing for other columns (the sum of the products of the values in each row of Col D and G and also Col C and G, and I don't want to click in every single cell and type * and , over and over again.

Please check:
Pedido de Material.xlsx

write an array formula ex. =sum(E2:E44*G2:G44) but instead of just hitting enter you need to hit control shift enter!!!

Thanks. Problem solved.