Acar salesman earns a base salary plus commission for every car he sells. the expression shows the amount a salesperson earns, if he sells x cars in a month.
2,000 + 1,000x
how much does he earn for each car sold?
a) $0
b) $1,000
c) $2,000
d) $3,000

The car salesman makes a base salary of $2,000. He also gets $1,000 for every car he sells. And it asks us, "How much does he earn for each car sold?"
 
The variable x is how many cars he sold. In this one.

Now the equation is this: 2000 + 1000(1)
Now solve.
2000 = 1000(1) = 2000 + 1000 = 3000

So our car salesman would have made $3,000 in a month.