Can someone please help me

D. (2,0) and (2,5) have the same x-value by different y-values

In other words, the input x = 2 leads to multiple outputs y = 0 and y = 5 at the same time. A function is where any input leads to exactly one output only (assuming that input is in the domain). So whenever x repeats itself like this is when we don't have a function.

answer: okw

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional