Answer:
The price of each burger is $4
The price of each order of fries is $2.5
Step-by-step explanation:
* <em>Lets explain how to change the story problem to equations</em>
- Jim bought 3 burgers and 2 orders of fries for $17
- Abby bought 2 burgers and 4 orders of fries for $18
- Assume that the price of one burger is x and one order of fries is y
* <em>Lets write two equations represents Jim and Abby orders</em>
∵ Jim bought 3 burgers and 2 orders of fries for $17
∴ 3x + 2y = 17 ⇒ (1)
∵ Abby bought 2 burgers and 4 orders of fries for $18
∴ 2x + 4y = 18 ⇒ (2)
* <em>Lets solve the two equations by the elimination method</em>
- Multiply equation(1) by -2 to eliminate y
∵ -2(3x) + -2(2y) = -2(17)
∴ -6x + -4y = -34 ⇒ (3)
- Add equations (2) and (3)
∴ -4x + 0 = -16
∴ -4x = -16
- Divide both sides by -4
∴ x = 4
- <em>Substitute the value of x in equations (1) or (2) to find y</em>
∵ 3x + 2y = 17
∴ 3(4) + 2y = 17
∴ 12 + 2y = 17
- Subtract 12 from both sides
∴ 2y = 5
- Divide the both sides by 2
∴ y = 2.5
∵ x represent the price of each burger
∴ The price of each burger is $4
∵ y represents the price
of an order of fries
∴ The price of each order of fries is $2.5
