The variables x and y vary directly. use the given values to write an equation that relates x and y: x = 4, y = -16

Vary Directly: y = k*x

Vary Inversely:  y = k/x

Because x and y vary directly, our equation will look like the first one.

y = k*x

With the inputted values:

-16 = k * 4

Now, to find k, isolate the variable

k = -16/4 = -4

Your final equation will then look like this:

y = -4 * x

step-by-step explanation:

through just a quick inspection, one can see that the graph of this cubing function starts in quadrant iii and ends in quadrant i.   when x = 0, y = 3, so the y-intercept is (0, 3).

if graphs are part of the problem statement, share them.   .