Question

10 granola bars and twelve bottles of water cost $23. 5 granola bars and 4 water bottles of water of water coat $10. how much does one granola and one water bottle cost

Answer 1

Answer:one granola costs $1.4

One bottle of water costs $0.75

Explanation:

Let x represent the cost of one granola.

Let y represent the cost of one water bottle.

10 granola bars and twelve bottles of water cost $23. It means that

10x + 12y = 23 - - - - - - - - - - - 1

5 granola bars and 4 water bottles of water of water cost $10. It means that

5x + 4y = 10 - - - - - - - - - - - 2

Multiplying equation 1 by 1 and equation 2 by 2, it becomes

10x + 12y = 23

10x + 8y = 20

Subtracting, it becomes

4y = 3

y = 3/4 = 0.75

Substituting y = 0.75 into equation 1, it becomes

10x + 12 × 0.75 = 23

10x + 9 = 23

10x = 23 - 9 = 14

x = 14/10 = 1.4

Answer 2

One granola costs $1.40.

One water bottle costs $0.75.

Explanation:

This question can be solved by a simple system of equations.

I am going to say that

x is the cost of each granola bar.

y is the cost of each bottle of water.

The first step is building the system:

10 granola bars and twelve bottles of water cost $23.

This means that:

10x + 12y = 23.

5 granola bars and 4 water bottles of water of water cost $10

This means that:

5x + 4y = 10

So we have to solve the following system of equations:

10x + 12y = 23

5x + 4y = 10

I am going to multiply the second equation by -2, and use the addition method. So:

10x + 12y = 23

-10x - 8y = -20

10x - 10x + 12y - 8y = 23 - 20

4y = 3

y = 0.75

y = 0.75 means that each water bottle costs 75 cents.

5x + 4y = 10

5x = 10 - 4y

5x = 10 - 4*0.75

5x = 7

x = 1.4.

x = 1.4 means that each granola costs $1.40.