Set 17: Systems of Equations (Advanced)

Choice C is correct. Choice C is the correct answer. Let $b$ be the number of books. Store 1: $C_1 = 15 b + 8$ Store 2: $C_2 = 18 b$ Set equal: $$$15b + 8 = 18 b8= 3 b$b = \frac{8}{3} \approx 2.67 Since we need whole books, round up to 3. - 2 books: Store 1 = $38, Store 2 = 36 dollars (not equal) - 3 books: Store 1 =$53, Store 2 = 54 dollars (close) Strategic Tip: Break-even problems compare two linear cost models. Choice A is incorrect because costs are $24 vs$18. Choice B is incorrect because costs are $39 vs$36. Choice D is incorrect because costs are $69 vs$72.