A tour group split into two groups when waiting in line for food at a fast
food counter. The first group bought 7 slices of pizza and 5 soft drinks
for $28.42. The second group bought 6 slices of pizza and 4 soft drinks
for $23.80. How much does one slice of pizza cost? Write your answer
without the $ sign.

Question

A tour group split into two groups when waiting in line for food at a fast
food counter. The first group bought 7 slices of pizza and 5 soft drinks
for $28.42. The second group bought 6 slices of pizza and 4 soft drinks
for $23.80. How much does one slice of pizza cost? Write your answer
without the $ sign.

anonymous · Answer

Let price of Pizza be X and SoftDrinks be Y. So the questons would be rephrased as the equation:

7X+5Y = 28.42  - Equation 1
6X+4Y = 23.80  - Equation 2

Find the value of X.

Multiply Equation 1 with 4 and Equation 2 with 5, So that the Coefficient of Y is same in both equations.

Equation 1 * 4 -> 28X+20Y = 113.68
Equation 2 * 5 -> 30X+20Y = 119

Now Subtracting Equation 1 from Equation 2

2X = 5.32, So X = 5.32/2 = 2.66

Hence the price of slice of Pizza is 2.66