Video Transcript
Karen receives a monthly allowance of 30 dollars from her father. She uses it to download movies. If the site charges seven dollars per month for the membership fee and each movie costs 2.55 to download, which of the following expressions represents how much allowance, in dollars, she will still have after she has downloaded 𝑥 movies? A) 23 minus 2.55𝑥, B) 2.55 times 𝑥 minus 30 plus seven, C) 37 minus 2.55𝑥, or D) 2.55𝑥 plus 37.
Let’s break down the values we were given. The first value we’re given is 30 dollars, and that is Karen’s monthly allowance. Next, we’re given seven dollars, which is a monthly membership fee. After that, we have two dollars and 55 cents, which is the cost per movie that Karen rents. And then, we’re given the variable 𝑥, which represents the number of movies Karen rented that month. We want to find out how much allowance Karen will have after she has downloaded 𝑥 movies. We start with her allowance and subtract the money she spent. We’ll get her remaining allowance.
So, she starts with 30 dollars but each month she has to spend seven dollars on her membership fee. So, from the 30 dollars we need to subtract seven. 30 minus seven is 23. And this 23 represents the money that Karen can spend on videos. It’s the amount she has remaining after she pays for her membership fee. If we know that each movie costs 2.55 and she’s going to purchase 𝑥 number of movies, we should multiply 2.55 by 𝑥, as 2.55𝑥 will be the money she spent on movies. From there, we can say that the money remaining will be equal to 23 minus 2.55𝑥. And this is option A, 23 minus 2.55𝑥.
We could look closely at the other options. In option C, the membership fee has been added to the allowance, and that doesn’t make sense. In option D, the membership fee and the allowance have been added together. And then they’ve added the cost of the movies to that value. So, these two won’t work. In option B, they’ve subtracted 30 from the number of movies that Karen would purchase in a month. And that will not help us. Only option A will produce how much allowance in dollars Karen will still have after she has downloaded 𝑥 movies under these conditions.
