Respuesta :

The answer is D. Even without plugging the answer choices in (which is an option), you know that 5 is 1/3 of 15 and 15 is 3 times 5. So if you multiply -15 by 1/3, you get -5. 
nobrains
Direct variation is written in the form y = kx, where k is the constant of proportioanlity. To find k, substitute the given values y = -5 and x = -15 into the direct variation equation y = kx and solve for k.

y = kx
(-5) = k(-15)
k = 1/3

Now we rewrite the equation using the value of k.
y = (1/3)x