Answer is (5/17 1/17).
( -2/17 3/17
You can first make the equations:
6x+4y=548
y-12=x
Here, you can use the substitution method and you get:
6(y-12)+4y=548
6y-72+4y=548
10y=620
y=62
Then there are 62 student tickets and 50 adult tickets.
Let

be the solid. Then the volume is

which follows from the facts that

(by computing the Jacobian)
and

(we take the positive solution, since it's clear that

lies above the

-

plane)

(again, taking the positive root for the same reason)





The total of the monthly bills will be $640.
(Add all of the bills together)