multiplying and adding problem

[alighouston]

hi all,
i am having problem with the following code how can i multiply hour and rate in the following query then add the values then following query works fine to retrieve the data and link it any ideas

PHP Code:

Select sum(hours.employ_hours)as hour
,hours.employ_name,empoly.employ_pay as rate
 from hours left join empoly 
on hours.employ_name=empoly.employ_name 
group by employ_name