Question

a salesman sold a total of 36 books and hats on Saturday. Each book costs 9$ and each hat costs 5$. He sold a total of 264 of product. How many of each did he sell

Answer 1

Let x be books and y be hats
x + y = 36 , x = 36-y
9x + 5y = 264
Substitute x
9(36-y) + 5y = 264
324-9y + 5y = 264
324-4y = 264
-4y = -60
y = 15
x = 36-15
x = 21
He sold 21 books and 15 hats.