Please i really need help

What is the product of the radical expression. (7-2square root) (8+2 square root)

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2

Scenario: 2 storage sheds are to have the same area. 1 is square and the other is rectangular. the rectangular shed is 4 meters wide and 9 meters long question: how large is one side of the square shed in meters?