Which of the following relations is a function?

a.
(1, 4), (-3, 6), (1, 3), (-7, 2)

b.
(1, 0), (-3, 3), (7, 1), (-3, 5)

c.
(1, 4), (-3, 2), (7, 1), (-7, 2)

d.
(7, 1), (-3, 4), (1, 1), (7, 2)
this is study island understanding functions

C is the correct answer.

Step-by-step explanation:

Look at the X values for each coordinate pair. If an X value is represented twice with different Y values, it is not a function. If no X value is repeated, or it is repeated but has the same Y value, then it is a function. A has two values for x = 1, B has two values for x = -3, D has two values for x = 7, but C does not, so it is the correct answer.

1) c 2143.6 cm

2) c 113.0 m

3) a 33.5 ft

4)   d 2 cm

5) c 20 mm

6) 180 in

7) d 120 ft

54.864 meters

step-by-step explanation: