Robert is purchasing some equipment for his baseball team. he wants to buy some baseballs, each priced at m dollars. he has already spent b dollars on other equipment.
if the amount already spent by robert on other equipment, b dollars, is doubled, then the value of m will doubled, not change, be half the original amount).
if the cost of each baseball, m dollars, is tripled, then the value of b will change, be tripled, be 1/3 the original amount) and the value of mx will change, be tripled, be 1/3 the original amount).