What he has left in the bank is here :
(123.17 + 34.68) - 50 = 107.8
He still has $107.8 left in the bank and he has $50 in his pocket.
I hoped I helped!
Answer:

Step-by-step explanation:
We are trying to evaluate this integral.

The first thing that we have to do is understand this region in the plane.

If you graph it looks something like the photo I join.
Now we need to describe that same region in polar coordinates.
That same region in polar coordinates would be

Now remember that when we do the polar transformation we use the following formula

Then our integral would be

There is usually calculator that will solve it for you look for them just plug the question in and it can show the steps too