Hassan paid $18.00 to buy 4 paperback books and 2 hardcover books. Aviv paid $36.25 to buy 5 paperback books and 5 hardcover books. The prices for all the hardcover books were the same, and the prices for all the paperback books were the same. What was the price of a hard cover book?
A. $7.25
B. $5.50
C. $4.50
D. $1.75

Step-by-step explanation:

Consider p the price of a paperback b and h the price of a hardcover b

we get :

4p + 2h = 18         (1)

5p + 5h = 36.25  (2)

if we multiply both sides of equation (1) by 5

and both sides of equation (2) by 4

then we get:

20p + 10h = 90      (3)

20p + 20h = 145    (4)

(4) - (3) → 10h = 55 then h = 55/10 = 5.5

8x^2-4x-5

Step-by-step explanation: