Find the constant of variation, k, for y=-8 when x=12.

I think it is 4 because its the biggest number that goes into 8 and 12

Direct Variation. Since k is constant (the same for every point), we can find k when given any point by dividing the y-coordinate by the x-coordinate. For example, if y y varies directly as x , and y = 6 when x = 2 , the constant of variation is k = = 3 . Thus, the equation describing this direct variation is y = 3x .