Question

A library is having a used book sale. All hardcover books

have the same price and all softcover books have the
same price. You buy 4 hardcover books and 2 softcover
books for $24. Your friend buys 3 hardcover books and
3 softcover books for $21. What is the cost in dollars of a
hardcover book?

Answer 1

Answer: It should cost $5

Explanation:

First you have 4 hardcover and 2 softcover, so 4x+2y= $24 and for your friend it would be 3x+3y= $21.

You have

(3x+3y)2 = 72

(4x+2y)3 = 42

Then subtract them which is 30 you would divide by 6 since 3x2=6

Which gets you to 5.

Answer 2

You have 4 hardcovers and 2 soft covers... soo the equation would be 4x+2y=$24
for the friend the equation would be 3x+3y=$21