Question

Look at these sets of ordered pairs.
W) {(8, 9), (2, 3), (0, -2), (10, -9)}
X) {(0, 0), (5, 10), (-3, 3)}
Y) {(1, 1), (2, 2), (3, 3), (4, 4)}
Z) {(-10, 1), (-9, 3), (-4, 5)}

Answer 1

first element of a FUNCTION must not repeat
like these example
{(1,2) ,(2,5)} is function

bu {(1,2) ,(2,5),(2,6)} is not
because 2 seems twice

Answer 2

do as this way