sql getting data three columns from one table and one from another -

i have 2 tables sales , customers 1st table want sum 2 columns recived_amount , bill_amount , subtract them both , after want customer_id

from 2nd table want customer_name

i've tried

  select customer_details.cus_name,         sum(sales.bill_amount) - sum(sales.recived_amount),        customer_details.cus_id   sales    inner join customer_details         on customer_details.cus_id=sales.cus_id   sales.cus_id = 1 order cus_id 

 select customer_details.cus_name, (sum(sales.bill_amount) - sum(sales.recived_amount))       subtract,customer_details.cus_id   sales inner join customer_details on customer_details.cus_id=sales.cus_id   sales.cus_id = 1    group customer_details.cus_name,customer_details.cus_id   order cus_id