4x = -y. Find the constant of variation k for the direct variation.

Question

anonymous · Answer

attachment

anonymous · Answer

@ganeshie8 do you think you could possibly help?

hartnn · Answer

direct variation is of the form

y= kx

so you just need to isolate y

you can do that by multiplying both sides by -1

anonymous · Answer

Oh! I've been so confused as to where the k always comes! Thank you! Alright, so I just need to isolate y?? How did you get -1, though? O.o Is that just the general thing to use in this situation?

anonymous · Answer

Oh, and I got -4 when I multiplied the 4 by -1.

hartnn · Answer

k = -4  is correct :)


and multiplying by -1 is not a general thing, 
i did it to isolate the 'y'
note that y was multiplied by -1 

to get +y, i multiplied -1 to -y

hartnn · Answer

if it were 
6y =  ... 
i would have divided both sides by 6
to get just y on left

anonymous · Answer

Oh..I think I get where the -1 came from. From what I think I remember, when there is something such as just a -y, there's basically an invisible 1 in front of the y, right? I think I recall learning something like that. And so the final answer is -4?

hartnn · Answer

yes, final answer is k =-4 :)

$ y = 1 \times y\  - y = -1 \times y $

anonymous · Answer

Ohh, okay, thank you :)

hartnn · Answer

welcome ^_^