When does the price of an item decrease?

We just started the introduction into circles and i have no idea how to do this.

36x2 + 49y2 = 1,764 the foci are located at: (-√13, 0) and (√13,0) (0, -√13) and (0,√13) (-1, 0) and (1, 0)edit: the answer is (- the square root of 13, 0) and (the square root of 13, 0)

Arectangular garden is 5 feet long and 3 feet wide. a second rectangular garden has dimensions that are double the dimensions of the first garden. what is the percent of change in perimeter from the first garden to the second garden?