Complex Sum formula

Struggling with a formula which requires excel to make a calculation(addition) and use the answer to multiply against another addition calculation....

eg:

The sum of (Monday!A1:A4) multiplied by the sum of (Monday!B1:B4) plus (Tuesday!A1:A4) multiplied by the sum of (Tuesday!B1:B4) and so on.....

is this do-able ????

Thanks

Try something like this....

=SUM(Monday!A1:A4)*SUM(Monday!B1:B4)+SUM(Tuesday!A1:A4)*SUM(Tuesday!B1:B4) 

Is that something you can work with?