Dante spent 1125 on 3 new and 4 old comic books and Samantha

Dante spent $11.25 on 3 new and 4 old comic books, and Samantha spent $15.75 0n 10 old and 3 new ones. If comics of one type are sold at the same price, what is the price in dollars of a new comic book? this is Systems of Equations problem

Solution

Let x= cost of new comic book

y = cost of old comic book.

Then the equations would be

3x + 4y = 11.25 ...(1)

3x + 10y = 15.75 .... (2)

Subtract (2) from (1),

6y = 4.5

y = 4.5/6 = $0.75

Substitute this in (1),

3x + 4(0.75) = 11.25

3x + 3 = 11.25

Subtract 3 from both sides,

3x = 8.25

Divide by 3 on both sides,

x = $2.75

So, x=$2.75 (New comic book)

and y= $0.75 (Old comic book)