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At a concession stand, 9 slices of pizza and 5 soft pretzels cost $33.25. If 6 soft pretzels and 4 slices of pizzas cost $19.50, what is the cost of a soft pretzel and a slice of pizza?

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sqdancefan
Let x and y represent the costs of a pizza slice and a soft pretzel, respectively. The two purchases can be described by ...
  9x +5y = 33.25
  4x +6y = 19.50

A graph shows the solution of these equations to be
  (x, y) = (3, 1.25)

The cost of a soft pretzel is $1.25.
The cost of a slice of pizza is $3.00.
Ver imagen sqdancefan
9x+5y=33.25
4x+6y=19.50
Multiply the first equation by 6 and the second one by 5 so the ys (soft pretzels) will cancel out and leave you with x (slices of pizza) so you should get:
54x+30y=199.50
20x+30y=97.50
Then subtract the equations leaving you with:
34x=102
X=3
So each piece of pizza is $3
Then plug 3 in for x to get y I’ll just use the first equation
27+5y=33.25
5y=6.25
Y=1.25
Each pretzels costs $1.25

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