Which set of ordered pairs represents a function? a
{(1, 8), (8, 1), (1, 5), (5, 1)}
{(2, 1), (3, 1), (4, 3), (5,3)}
{(5, 1), (3, 8), (3, 7), (7, 1)}
{(5, 1), (5, 6), (1,3), (9, 7)}

see explanation

step-by-step explanation:

since the sequence is geometric there is a common ratio r between consecutive terms, that is

r = 4 ÷ - 2 = - 2

r = - 8 ÷ 4 = - 2

r = 16 ÷ 8 = - 2

the next term - 13 must be incorrect as it should be - 32 for the sequence to be geometric.

the first 4 terms are therefore geometric with common ratio r = - 2