Please solve this worksheet. (Factoring trinomials)

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

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?

What is the area of the original rectangle? 8 cm² 20 cm² 25 cm² 40 cm²