" Tickets to the musical cost $8.00 for students and $12.00 for others. If $520.00 was earned by the sale of 49 tickets, how many student tickets were sold?"

Let s = number of tickets for sudents sold.

And x = number of tickets for others sold.

s +x = 49 ---(1)

s(8.00) +x(12.00) = 520.00

8s +12x = 520

Divide both sides by 4,

2s +3x + 130 ----(2)

From (1),

x = 49 -s

Substitute that into (2),

2s +3(49 -s) = 130

2s +147 -3s = 130

2s -3s = 130 -147

-s = -17

s = 17 students ticket sold. -----answer.

Check,

x = 49 -s = 49 -17 = 32 tickets for others sold.

s(8.00) +x(12.00) = 520.00

17*(8.00) +32*(12.00) =? 520.00

136.00 +384.00 =? 520.00

520.00 =? 520.00

Yes, so, okay.