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

B) $1,000

Explanation:
We know that the total amount he receives is the summation of:
1- fixed salary, this one is fixed and does not depend on any variables
2- commission, this one is changing depending on a variable which is the number of cars he sold

The given expression for what he receives is:
2000 + 1000x
Let's check each term:
2000 : this one is fixed and doesn't depend on any variables. This means that $2000 is his fixed salary
1000x : this one is changing depending on the value of x which represents the number of cars sold. This means that $1000 is his commission per car

Hope this helps :)