Answer: {(7,1),(7,-7),(-8,3),(9,5)}
Explanation:
Ordered pairs are written as (x,y) where x-coordinate is the input and y-coordinate is the output. Each input (x) must be given once and each input (x) has exactly one output (y) for pairs to represent a function.
In the option, (7,1) and (7,-7), input x=7 appears twice. Therefore, 7 will be paired twice with 1 and -7. Thus, cannot be a function.