google sheets

When I input details of sold item in sheet "Daler", "Sales" spreadsheet, then I want quantity of sold item to be deducted in inventory in "Relad". Simply I want Inventory in "Relad" gets updated automatically when sales details has been inserted on spreadsheet "Sales" on sheet "Daler". Also, sometimes I receive new stock and add to "inventory" spreadsheet in "Relad" sheet so is it possible to update that part too?

https://docs.google.com/spreadsheets/d/1bWd57bj0lZsMLKqoiF0Az2_hrCcB2iwZctXbxlzwy9Y/edit#gid=0

https://docs.google.com/spreadsheets/d/1VvuM78euij_zdsphkN_Q-ORC91zJl545ya02v7VKHxc/edit#gid=1781986773