#1**+1 **

A. Two equations - Two Unknowns...we can solve by the elimination method

B. Let x be the price of the hardcover book and y be the price of the paperback...and we have

4x + 10y = 64

5x + 7y = 58

C. Multiply the top equation through by 5 and the bottom equation through by -4 and we get

20x + 50y = 320

-20x - 28y = -232 add these

22y = 88 divide both sides by 22

y = 4 ⇒ cost of paperback in dollars

And using 4x + 10y = 64, the cost of the hardback can be found as

4x + 10(4) = 64

4x + 40 = 64 subtract 40 from both sides

4x = 24 divide both sides by 4

x = 6 ⇒ cost of hardback in dollars

CPhill
Sep 20, 2018