The Tables represent two linear functions in a system. What is the solution to this system

What is the rescursive formula for this geometric sequence? 7, -14, 28, -56

For each proportion find the unknown number x 1/5/8=×/15

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?