Question

The total cost of 4 sodas and 6 patties is $840. If a customer buys 5 sodas and 5 patties, the total cost is $800. What is the cost of 1 soda and 1 patty?​

Answer 1

S = $76 and P = $236

Explanation:

Let the sodas be S and the patties P. So

4S + 6P = 840 and 5S + 5P = 800

By substitution method we will have the solution

5S + 5P = 800

5S = 800 - 5P

S = 800 - 5P

5

We'll sustitute S with this equation

4S + 6P = 840

`4((800 - 5P)/(5))` + 6P = 80

4(800 - 5P) + 6P(5) = 840

3200 - 20P + 30P = 840

-20P + 30P = 840 - 3200

10P = -2360

P = -2360

10

P = -236

Since the cost of the patty can't be negative, P = $236

Now that we know the cost of the patty, we can calculate the cost of the soda

S = 800 - 5P

5

S = 800 - 5(236)

5

S = 800 - 1180

5

S = -380

5

S = -76

Here S can't be negative, so S = $76