Which of the ordered pairs is not a function?

(1) { (0,9), (9,0), (1,2), (3,4) }

(2) { (0,1), (-1,0), (1,2), (3,2) }

(3) { (2,3), (3,4), (4,5), (5,6) }

(4) { (2,3), (2,4), (4,5), (4,6) }

On a test eddie solved the equation 5/x-2 - 20/x^2 - 4=1 and found that x=2 and x=3 his steps where correct so why was his answer marked wrong?

Are there less than 1 million exactly 1 million or greater than 1 million miligrams in a kilogram?

What is 7+89 and divided by 5

Find the greatest common factor of 21

17+6p=9 liner equation

A college conducted a survey to explore the academic interests and achievements of its students. It asked students to place checks beside the numbers of all the statements that were true of them.

Find the average of the list of numbers. - 18, - 29, - 17, - 12

What does supplementary mean

A cookie recipe calls for 1/4 cup of brown sugar for one batch of 24. How many cups of brown sugar would be needed to bake 144 cookies

For which function is f (x) not equal to f-1 (x) ? A - f (x) = 2-x B-f (x) = 2/x C=f (x) = - x D=f (x) = 2x