1)
The school that Carlos goes to is selling tickets to a choral performance.
On the first day of ticket sales the school sold 14 senior citizen tickets and 6 student tickets for a total of $180.
The school took in $117 on the second day by selling 12 senior citizen tickets and 1 student ticket.
Find the price of a senior citizen ticket and the price of a student ticket.
x = senior citizen ticket price
y = student ticket price
\(\begin{array}{|lrcll|} \hline (1) & 12x+1y &=& $117 \\ & y &=& 117 - 12x \\\\ (2) & 14x+6y &=& $180 \\ & 14x+6(117 - 12x) &=& $180 \quad &| \quad :2 \\ & 7x+3(117 - 12x) &=& 90 \\ & 7x+ 351 - 36x &=& 90 \\ & 351 - 29x &=& 90 \quad &| \quad + 29x \\ & 351 &=& 90 + 29x \quad &| \quad - 90 \\ & 261 &=& 29x \quad &| \quad : 29 \\ & 9 &=& x \\ & \mathbf{x} & \mathbf{=} & \mathbf{$9} \\\\ & y &=& 117 - 12x \quad &| \quad x=9 \\ & y &=& 117 - 12(9) \\ & y &=& 117 - 108 \\ & y &=& 9 \\ & \mathbf{y} & \mathbf{=} & \mathbf{$9} \\ \hline \end{array}\)
The price of a senior citizen ticket is $9.
The price of a student ticket is $9.
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