There are 19 dogs the owner gave away 9 how many are left?

Acircular city park has a sidewalk directly through the middle that is 111 - feet long. if each bag of fertilizer covers 50 square feet, then determine how many bags of fertilizers the parks and recreation department needs to use to cover the circular park. ignore all the sidewalks around and through the park.

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

If f(x)=x+7 and g(x)=1/x what is (fog)(x)