query for sum of columns in two separate tables

[webguy262]

I'm trying to get the sum of column A in table X and of column B in table Y.

 

I need these as two separate sums, not looking to add them together.

 

Here's what I have, but it is giving wrong results:

 

Select sum(novo_billing.balance) as sum_balance, sum(novo_payments.payment) as sum_payment from novo_billing, novo_payments