5 hockey pucks and three hockey sticks cost $23. 5 hockey pucks and 1 hockey stick cost $20. How much does 1 hockey puck cost?

Respuesta :

Answer:

  $3.65

Step-by-step explanation:

The two purchases describe relations between quantity and price that can be used to write a system of equations for the prices of the hockey pucks and hockey sticks. These equations can be solved to find the price of a hockey puck.

__

setup

Let x and y represent the prices of a hockey puck and a hockey stick, respectively. The two purchase values are ...

  5x +3y = 23.50

  5x +y = 20.00

solution

Rearranging the second equation, we have an expression for y:

  y = 20.00 -5x . . . . . . subtract 5x from both sides

Substituting this into the first equation gives ...

  5x +3(20.00 -5x) = 23.50 . . . . . substitute for y

  -10x +60.00 = 23.50 . . . . . . simplify

  x -6.00 = -2.35 . . . . . . . . divide by -10

  x = 3.65 . . . . . . . . . . . add 6

One hockey puck costs $3.65.