Can someone explain to me how to solve this kind if problems?

Giving 100 points asap bev has to cut her grandma's grass this weekend and wants to know exactly how much area she will be cutting. calculate the area of the polygon. be sure to show all your work and explain your answer.

Which expression is equivalent to the expression shown?

Luke wants to reduce the area of his rectangular garden by 1/4 the expression 14/w can be used to represent this change. what is another way to write this expression?