Which relation is a function? {(1, 2); (2, 3); (3, 4); (1, 5)}

{(1, 2); (1, 3); (3, 2); (4, 2)}

{(1, 2); (2, 5); (3, 2); (4, 5)}

{(1, 2); (2, 3); (3, 4); (2, 5)}

the third relation: {(1, 2); (2, 5); (3, 2); (4, 5)}

Step-by-step explanation:

relations can only be a function if the input/x don't repeat at all.

its ok if the output/y repeat though!

3/4 ÷ 3/4

step-by-step explanation:

basically divide any proper fraction with itself to fit the criteria.

so if we are using 3/4, then:

3/4 ÷ 3/4 = 1

so 1 is the quotient.

and the numerators for both these fractions is 3.   and if we divide the numerators:

3 ÷ 3 = 1

we see that quotient is equal to our original quotient as well.