Isolating Variables in Real-World Math Word Problems

A store sells x notebooks for $p each and charges a flat fee of $q. If the total cost is $r, how can you find the price per notebook?

• (r - x) / p

• r / (x + q)

• (r - q) / x

• (r + q) / x

You have a budget of $r to spend on x items that cost $p each, plus a shipping fee of $q. How can you determine how many items you can buy?

• x = (r + q) / p

• x = (r - q) / p

• x = (r - p) / q

• x = (r * p) + q

A car rental company charges a base fee of $q plus $p per day for renting a car. If your total bill is $r, how can you isolate the number of days you rented the car?

• d = (r - p) / q

• d = (r + q) / p

• d = (r - q) / p

• d = r / (q + p)

In a recipe, you need p cups of flour and q cups of sugar to make x cookies. If you want to make r cookies, how can you express the amount of flour needed in terms of r?

• (p/x) * r

• (p + q) * r

• (q/x) * r

• (p/q) * r

A gym membership costs $p per month plus a one-time fee of $q. If you want to spend a total of $r, how can you find out how many months you can afford the membership?

• (r - p) / q

• (r - q) / p

• (p + q) / r

• (r + q) / p

You are saving $p each week and have a goal of $r. If you already have $q saved, how can you find out how many weeks it will take to reach your goal?

• (r + q) / p

• (q - r) / p

• (r - p) / q

• (r - q) / p

A phone plan costs $p per month plus a one-time activation fee of $q. If your total cost for the first month is $r, how can you isolate the monthly fee?

• p = r / q

• p = r - q

• p = r + q

• p = r * q

You are buying x tickets to a concert that costs $p each, plus a service fee of $q. If your total cost is $r, how can you find the price of each ticket?

• p = r / (x + q)

• p = (r - q) / x

• p = (r * x) + q

• p = (r + q) / x

A landscaping service charges $p per hour plus a flat fee of $q. If your total bill is $r, how can you determine how many hours of service you received?

• r / (p + q)

• (r + q) / p

• (r - p) / q

• (r - q) / p

You are planning a party and need to buy x pizzas at $p each, plus a delivery fee of $q. If your total budget is $r, how can you find out how many pizzas you can order?

• x = (r + q) / p

• x >= (r - q) * p

• x = r / (p + q)

• x <= (r - q) / p