What is the no solution, the one solution, and the infinitely many solution of 2x+5+2x+3x

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.

Asphere has a diameter of 10 in. what is the volume of the sphere?

What is the solution for 6 - 7/8? explain the steps.