Maria buys lunch every work day. She always eats at the same restaurant and spends no more than $5.25 for lunch. She has created a budget in which she has allowed herself $1700 for the year to buy lunches during her five-day work week. Assume Maria spends the maximum she allows for each lunch. Write an equation to determine how much of her budget, in dollars, remains unspent at the end of a particular week of the year?