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10 votes
10 votes
8. Mr. Hall has $216 to spend on supplies for his classroom. He will buy a bookshelf and some books. The bookshelf costs $81. He will buy books that cost $3 each. Which inequality can be used to find all the possible numbers of books (x) that Mr. Hall can buy?

8. Mr. Hall has $216 to spend on supplies for his classroom. He will buy a bookshelf-example-1
User Myluco
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1 Answer

22 votes
22 votes

We can express an inequality that describes this situation like this:

From the statement of the question, we are told that Mr. Hall has $216, then he can spend no more than this amount, then we can express:

spent money ≤ available money

spent money ≤ 216

Now, from the given information, we know that the money is spent buying a bookshelf and some books, then the spent money would be the cost of the bookshelf plus the total cost of all the books.

spent money ≤ 216

Bookshelf cost + books cost ≤ 216

From the statement of the question, we know that the bookshelf cost equals $81 and that each book costs $3, the total books cost equals the cost per book times the number of books x, then we rewrite the expression like this:

Bookshelf cost + books cost ≤ 216

81 + 3*x ≤ 216

From this inequality, if we solve for x, we get:

81 - 81 +3x ≤ 216 - 81

3x ≤ 135

3x/3 ≤ 135/3

x ≤ 27

Then, the answer is x ≤ 27

User Felixgaal
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