Need i will mrk brainliest! the variables y and x have a proportional relationship, and y = 12 when x = 5. what is the value of y when x = 8? enter your answer in the box. y=

y = kx for a proportional relationship

12 = k*5

divide each side by 5

12/5 = k

y = 12/5 x

if x=8

y = 12/5 * 8

y = 96/5

y = 19 1/5

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