Question 296786
Start with your equations...let x be adult and y be student

If there were 700 tickets sold then equation 1 is x+y=700
and there was $13330 sold so equation 2 is 25x+15y=13330

1) x+y=700  you can rearrange this..subtract y from both sides so
that x=700-y
2) 25x+15y=13330

since we know that x=700-y we can sub that into equation 2

25(700-y)+15y = 13330
17500-25y+15y = 13330
17500-10y=13330   subtract 17500 from both sides
-10y= -4170  divide both sides by -10
y=417  so now you can go back and use y=417 in equation 1.

x+417=700  subtract 417 from both sides
x=283
so they sold 283 adult tickets and 417 student tickets
Hope this helps