For each of the following binary relations rho on Z, decide which of the given ordered pairs belong to rho. x rho y doubleheadarrow x|y, (2, -6), (3, 5), (8, 4), (4, 8) x rho y doubleheadarrow x and y art are relatively prime; (5, 8), (9, 16), (6, 8), (8, 21) x rho y doubleheadarrow gcd (x, .y) = 7; (28, 14), (7, 7), (10, 5), (21, 14) x rho y doubleheadarrow x^2 + y^2 = z^2 for some integer; (1, 0), (3, 9), (2, 2), (-3, 4) x rho y doubleheadarrow x is a number from the Fibonacci sequence; (4, 3), (7, 6), (7, 12), (20, 20)