A college student has $240 to use for laundry money. Each time he does laundry, he spends $7.50. Which equation represents the amount of money, M, he has after he has done laundry “x” times?
A) M= 7.50x - 240
B) M= 240 - 7.50x
C) M= 7.50 - 240x
D) M= 240x - 7.50