If y varies directly as x, and y = 15 as x = -3, find y for the x-value of 6.

Question

anonymous · Answer

and If y varies directly as x, and y = 16 as x = 4, find y for the x-value of 2.

shinalcantara · Answer

Since this involves direct variation and that 'y' is the dependent variable then you'll have it in the form:
y = kx
where k is the constant of proportionality
---------------
to find 'k', all you have to do is substitute the values y=15 and x=-3

shinalcantara · Answer

y = kx
15 = k(-3)
k = 15/(-3)
k = ?

shinalcantara · Answer

the reason why we need to find 'k' is for us to find 'y' when 'x' has a different value.
hence we'll have it as
y = kx
where x this time is 6 and for you to find 'y' you have to have the value of k

shinalcantara · Answer

in which case, k is?

shinalcantara · Answer

@bribee123

anonymous · Answer

k would be -5 right?

anonymous · Answer

Ohhh, I get it! Thanks so much!