Question

determine whether y vaires directly with x. If so, find the constant variation.
y=12x

Answer 1

for y varies directly with x, you should have
y=kx
where k is constant of variation.
does this help ?

Answer 2

what does constant of variation mean? Do i plug in12 for k?

Answer 3

yes!
compare y=kx with y=12x
u get k= 12
which is your constant of variation.
the first question was whether y varies directly with x
if y varies directly with x, then we write y=kx, which is of the form y=12x
so yes.
constant of variation just tells by how many times y is greater than x

Answer 4

okay so what would be an example of when it doesnt?

Answer 5

y vaires directly with x is y [alpha ] x
Thus y = kx where k is the proportionality constant
Hence y=12x implies k = 12

Answer 6

yes
y varies directly as x

Answer 7

like when y= ax+b (ex. y=12x+9)
this is not direct variation

Answer 8

okay then for the ones that dont how do i find their constant variation

Answer 9

constant of variation does not exist if there is no direct or inverse variation.

Answer 10

oh yes i get it. okay for this question i would put yes, the constant variation is 12 because y=kx which translates to y=12?

Answer 11

yes. is correct.
k=12, correct
'.....translates to y=12x '

Answer 12

okay thank you so much my teacher did not explain how to do these well but i get it now its actually really simple then on how to determine them right?

Answer 13

yes, its simple :) just practice few problems, then u will do it orally...no need to even write anything...

Answer 14

thank you so much @hartnn you helped so much :)

Answer 15

my pleasure :)
welcome.