Answer:
$5.27 each
Step-by-step explanation:
<em><u>EQUATION 1:</u></em>
--> Price of each story book: x
--> Quantity of story books: 3
--> Price of 3 story books: 3x
--> Price of each comic book: y
--> Quantity of comic books: 4
--> Price of 4 comic books: 4y
--> Total amount: $28.87
--> Equation----> 3x + 4y = 28.87
<u><em>EQUATION 2:</em></u>
--> Price of each story book: x
--> Quantity of story books: 4
--> Price of 3 story books: 4x
--> Price of each comic book: y
--> Quantity of comic books: 3
--> Price of 4 comic books: 3y
--> Total amount: $28.87 - 2.69 = $26.18
--> Equation----> 4x + 3y = 26.18
<em><u>SOLVE:</u></em>
3x + 4y = 28.87 <em>(Multiply by 4)</em>
4x + 3y = 26.18 <em>(Multiply by -3)</em>
--> 12x + 16y = 115.48
--> -12x - 9y = -78.54
<em>12x-12x will be cancelled.</em>
--> 16y-9y = 115.48-78.54
--> 7y = 36.94
--> y = 5.27
Therefore, each comic book cost $5.27.