Question

John paid $34 for two algebra and three geometry books. he paid $36 for three algebra and two geometry

Answer 1

Question: 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: The cost of each algebra book is $8 and the cost of each geometry book is $6.

Explanation:

a= algebra book cost

g= geometry book cost

Here's what we know:

2a + 3g = 34 (the 2 alg and 3 geo comes to $34)

3a + 2g = 36 (the 3 alg and 2 geo comes to $36)

This is a classic elimination method problem. I suggest that we multiply the first equation by -2 and the second by 3. This way, we can eliminate the variable g and still keep the other parts of the problem in the positive range:

-4a - 6g = -68

9a + 6g = 108

-------------------

5a = 40

Divide by 5:

a = 8

Now to solve for g:

2 * 8 + 3g = 34

16 + 3g = 34

3g = 18

g = 6

check (by using the second equation):

3 * 8 + 2 * 6 = 36

24 + 12 = 36

Answer 2

Each geometry book costs $6, each algebra book costs $8.

Let a=cost of one algebra book and g=cost of one geometry book. We have:

2a + 3g = 34-------->6a + 9g = 102

3a + 2g = 36-------->6a + 4g = 72

-------------------

5g = 30

g = 6

2a + 3(6) = 34

2a + 18 = 34

2a = 16--->a = 8