Question

ten granola bars and 12 bottles of water cost $23. 5 granola bars and four bottles of water cost $10. how much do one granola bar in one bottle of water cost?

Answer 1

Explanation:

I. 10x + 12y = 23

II. 5x + 4y = 10

I - 2*II

4y = 3 --> y = 3/4 = 0.75

5x + 4*3/4 = 10

5x + 3 = 10

5x = 7

x = 7/5 = 1.40

One granola bar cost 1.40 and one bottle of water cost 0.75

Answer 2

2.15

Explanation:

Let g= cost of granola bars

b = cost of bottles of water

10g+12b =23

5g +4b = 10

I will solve this system by elimination

Multiply the second equation by -2

-2(5g +4b) = -2*10

-10g -8b = -20

Now we add this equation to the first equation to eliminate g

-10g -8b = -20

10g+12b =23

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

4b = 3

b = 3/4

A bottle of water = $.75

Now we need to find g

5g+4b =10

5g +4(.75) = 10

5g +3 = 10

Subtract 3 from each side

5g +3-3 = 10-3

5g =7

Divide by 5

5g/5=7/5

g = 7/5

g = 1 2/5

g =1.40

We want the cost of one bottle of water and 1 granola bar

1g + 1b

1.4+.75

2.15