Let the side of each side of photo is a inch.
So area of photo = (side)^2 =

But as given area of photo is 9 square inch.
So


So side of photo is 3 inch.
Answer:
20.48
The parentheses just means multiplication.
A = {x ≥ 3}, B = {x ≤ 1}
So A∪B = {x ≥ 3 or x ≤ 1}
So for x ⊆(1,3), A∪B = ∅
Apparently, (1,3) covers the first option, a will be the answer
2.666. The 6 is repeating