Nick is given $50 to spend on a vacation . He decides to spend $5 a day. Write an equation that show

Nick is given $50 to spend on a vacation . He decides to spend $5 a day. Write an equation that shows how much money Nick has after x amount of days.

Set up the function M(x) where M(x) is the amount of money after x days. Since spending means a decrease, we subtract to get:
M(x) = 50 - 5x