Question

Which set of ordered pairs does not represent a function?

\{(-3, -9), (7, 9), (9, 1), (7, 3)\}{(−3,−9),(7,9),(9,1),(7,3)}
\{(-3, 8), (-6, 5), (-5, -6), (1, -6)\}{(−3,8),(−6,5),(−5,−6),(1,−6)}
\{(3, 1), (-2, -9), (6, -9), (4, 6)\}{(3,1),(−2,−9),(6,−9),(4,6)}
\{(4, 3), (-4, 4), (-2, -5), (6, 4)\}{(4,3),(−4,4),(−2,−5),(6,4)}

Answer 1

2nd equation does not pass the vertical line test

(7,9) (7,3) (x,y)

because one x (input) should have one y (output)

however, one y (output) can have multiple x (inputs)