Final answer:
The variable 'x' represents the amount earned per box of Scout cookies. The expression simplifies to 120x, indicating total earnings for a case.
Step-by-step explanation:
Part A: The variable x represents the amount of money earned per box of Scout cookies. Since a case contains multiple boxes of cookies, the total earnings from a case are calculated by multiplying the earnings per box by the total number of boxes in a case.
Part B: To simplify the expression, you multiply the coefficients (numerical values) while keeping the variable intact. In
this case, the expression simplifies to 120x dollars because 10 cartons times 12 boxes per carton equals 120 boxes in total. Therefore, your earning for selling a whole case is 120 times the amount you earn per box.