Answer:
Youth ticket = $21
Adult ticket = $39
Explanation:
We'll call adult tix x and child tix y. Based on the information given, we can make these two equations:
7x + 12y = 525
x - y = 18
Start by putting x in terms of y with that second equation
x = y + 18
Then substitute that into the first equation:
7(y+18) + 12y = 525
Then solve for y
7y + 126 + 12y = 525
19y = 399
y = 21
If we want the adult price as well, we know
x - 21 = 18
x = 39
Checking the math:
7(39) + 12(21) = 273 + 252 = $525