Answer
y=-5x
y=-60 when x=12
Work Step by Step
Since the form of a direct variation is y=kx, we can substitute the point given to us into this equation:
125=-5k
Now lets solve for k, in order to create a general equation for this problem:
125=-5k (Divide both sides by -5)
-25=k
Now, substitute this value of k into our original equation:
y=-5x
In order to find y when x=12, substitute that value of x into the equation that we just found:
y=-5(12) (Simplify)
y=-60
