Question 222437
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Let *[tex \Large a] represent the number of adult tickets sold.  Let *[tex \Large c] represent the number of child tickets sold.  Since adult tickets cost $7.50 each, *[tex \Large 7.5a] is the amount of money collected for adult tickets.  Likewise, *[tex \Large 4.5c] is the amount of money collected for child tickets.


Now you can create a system of equations, one equation for the number of tickets sold and one equation for the value of the tickets sold:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \left\{\text{1:\ \ }\ \ \,a\ +\ c\ =\ 80\cr\text{2:\ \ }7.5a\ +\ 4.5c\ =\ 540\right]


Solve the system for *[tex \Large a] and *[tex \Large c].  Since the coefficients in Equation 1 are both 1, I recommend the substitution method.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
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