Answer:
Step-by-step explanation:
Let x represent the number of baseballs that Robert brought. The cost of each baseball is m dollars. This means that the cost of x baseballs will be $mx
The following expression represents the total amount Robert will spend after buying x baseballs.
Total amount = mx + b
If the amount already spent by Robert on other equipment, b dollars, is doubled, then the value of m will remain the same.
If the cost of each baseball, m dollars, is tripled, then the value of b remains the same and the value of mx will be 3mx