Which of the following is not a function? a(3,1), (-3, 2), (4, 5), (-4, 5), (0, 0)
b(1, 2), (3, 4), (1, 5), (5, 7), (2, 4)
c(-4, 1), (-2, 3), (-1, 5), (0, 6), (-3, 5)
d(1, 3), (2, 3), (4, 5), (6, 4), (8, 9)
please help I'm timed.

Adam plans to choose a video game from the section of the store where everything is 75% off. he writes the expression d-0.75d to find the sale price of the game if the original price is d dollars. gena correctly writes another expression, 0.25d, that will also find the sale price of the game if the original price is d dollars. use the drop down menus to explain each part of adams and rena's expression

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

Pls i’m super dumb and i need with this one it’s due tomorrow