از چرایی و چیستی؟

(2)  don't study = fail

--------------------  

(1) + (2)  ----->   study + don't study  = fail + don' fail  .   ok ?

study ( 1+don't) = fail ( 1+ don't )       ok ?

study ( 1+don't) = fail ( 1+ don't(

study  =   fail   !   

so  , don't study   

بعد هم بگید ریاضی بد !