Question 994427
A is cost of adult ticket
S is cost of student ticket

7A+4S=165
3A+4S=105
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7A+4S=165
-3A-4S= -105, multiplying by -1
4A=60
A=$15
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first equation
105+4S=65
4S=60
S=$15
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check with second
45+60=105
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Both groups have $15 tickets.