I am developing report in RDLC (VS 2012)

below is my report
In this report i have two group total value matrix table.
I want to minus Sum(income) and sum(expenses).
Total should be show as 2121.00
how its possible ?
[![Report Output](https://i.stack.imgur.com/RP9O6.png)](https://i.stack.imgur.com/RP9O6.png)

[![Report in Design mode](https://i.stack.imgur.com/WeYQF.png)](https://i.stack.imgur.com/WeYQF.png)