John paid $34 for two algebra and three geometry books. He paid $36 for three algebra and two geometry books. What is the cost of each book?



Answer :

Let the price of single algebra book = x
and the price of geometry book = y

Then equation (1) = 2x+3y=34
3y= (34 - 2x)
y= (34 - 2x)/3

And equation (2) = 3x + 2y=36

put value of y in equation (2)

3x + 2 (34-2x)/3= 36
9x + 2 (34-2x)=108
9x + 68 - 4x=108
5x=40
x=8
put x=8 in equation ( 1 )

2(8) + 3y= 34
16+3y=34
3y=18
y=6
Hence, price of algebra book = 8$ and price of geometry book=6$