Sales - expenses formula

This simple for most but I am a new user, can someone help with business formula example a2 sales - f2 expenses = j2 net ? i tried sum=(a2-f2)=j2 and sum=(a2-f2)j2 and got no result, please help

Lets say your sales is 100, expenses is 80, and so your net should be 100-80=20. In cell A2 enter 100, in F2 enter 80, in J2 enter
=A2-F2


Mangesh