Can someone help me with all of these questions​

Factor completely. 4p^2 + 36p + 81 express the answer in the form (ap + b)^2

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

What are the solutions of the equation x4 – 5x2 – 14 = 0? use factoring to solve. someone !