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31 votes
31 votes
A waitress sold 12 ribeye steak dinners and 15 grilled salmon dinners, totaling $599.82 on a particular day. Another day she sold 26 ribeye steak dinners and 5 grilled salmon dinners, totaling $582.98. How much did each type of dinner cost?

User Voldy
by
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1 Answer

24 votes
24 votes

Answer:

  • steak: $17.41
  • salmon: $26.06

Explanation:

You want to know the cost of each type of dinner when 12 steak dinners and 15 salmon dinners were sold for $599.82, and 26 steak dinners and 5 salmon dinners were sold for $582.96.

Setup

The two sales can be written as equations, where x is the cost of a steak dinner and y is the cost of a salmon dinner:

12x +15y = 599.82

26x +5y = 582.96

Solution

We can solve this system of equations by elimination. Subtracting the first equation from 3 times the second gives ...

3(26x +5y) -(12x +15y) = 3(582.96) -(599.82)

66x = 1149.06 . . . . simplify

x = 17.41 . . . . . . . . . divide by 66

Substituting for x in the first equation, we have ...

12(17.41) +15y = 599.82

15y = 390.90 . . . . . . . . . subtract 208.92

y = 26.06 . . . . . . . . . . . divide by 15

A ribeye steak dinner costs $17.41, and a grilled salmon dinner costs $26.06.

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Additional comment

The problem statement here gives the second dinner value as $582.98. We believe that is a typo, as the resulting individual dinner costs do not come out to whole cents that way. That is why we have used the value $582.96 instead.

User Crocked
by
2.7k points