Hello mathematicians help me pls Multiply (x + 1)^2

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

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field