Which of the following expressions represents a function?

a) x^2 + y^2 = 9
b) {(4, 2), (4, –2), (9, 3), (9, –3)}
c) x = 4
d) 2x + y = 5

Anew landowner is interested in constructing a fence around the perimeter of her property. her property is 1,080√30 feet wide and 500√20 feet long. what is the perimeter of the property? (recall that the perimeter is the sum of each side of a shape or boundary). a 1,580√40 feet b. 5,320√5 feet c. 3,160√20 feet d. 10,640√5 feet