To determine the valid combinations of books (x) and magazines (y) that the bookstore can order, we need to check each option against the given inequalities:
- Cost Inequality: \(15x + 5y \leq 1000\)
- Space Inequality: \(2x + y \leq 50\)
Let's analyze each option.
Option A: 50 books and 0 magazines (x = 50, y = 0)
- Cost: \(15(50) + 5(0) = 750 \leq 1000\) (satisfied)
- Space: \(2(50) + 0 = 100 \not\leq 50\) (not satisfied)
Option A is NOT valid.
Option B: 20 books and 15 magazines (x = 20, y = 15)
- Cost: \(15(20) + 5(15) = 300 + 75 = 375 \leq 1000\) (satisfied)
- Space: \(2(20) + 15 = 40 + 15 = 55 \not\leq 50\) (not satisfied)
Option B is NOT valid.
Option C: 40 books and 5 magazines (x = 40, y = 5)
- Cost: \(15(40) + 5(5) = 600 + 25 = 625 \leq 1000\) (satisfied)
- Space: \(2(40) + 5 = 80 + 5 = 85 \not\leq 50\) (not satisfied)
Option C is NOT valid.
Option D: 10 books and 30 magazines (x = 10, y = 30)
- Cost: \(15(10) + 5(30) = 150 + 150 = 300 \leq 1000\) (satisfied)
- Space: \(2(10) + 30 = 20 + 30 = 50 \leq 50\) (satisfied)
Option D is valid.
Conclusion: the only valid combination the bookstore can order is:
D. 10 books and 30 magazines