There are many possible answers for this.
One example is below.
<em>S = the number of stations included when a person orders basic cable, write an expression for the number of stations a person has if he ordered basic cable and 7 premium channels.</em>
We can represent this as s + 7.
The value that we don't know is the number of
stations included when a person orders basic cable.
So we can represent that as s.
Then, since the person ordered 7 premium channels, that means he
is adding an additional 7 channels to his basic cable plan.
So we can represent this as s + 7.
