Explanation: The equation for direct variation is y = kx^n, where k is the constant of variation. n is the exponent above the x value, but since this problem doesn’t involve exponents greater than one, we can ignore it.
First, find k. y = kx 6 = k*15 k = 6/15 or 2/5
Now, we can solve for any x or y input. Let’s find x when y = -4. y = kx -4 = 2/5 * x (to cancel out the fraction, multiply each side of the equation by its reciprocal, 5/2) x = -4 * 5/2 x = -20/2 x = -10
is given by the equation 