Question 223687
you made a mistake in your setup.
7.5x+4.5y=540
x+y=80, y=80-x
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7.5x+4.5(80-x)=540
7.5x+360-4.5x=540
3x=180
x=60
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7.50*60=$450
4.50*20=$90
total=$540
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I hope this helps.
Bob