For each equation, determine whether it shows a direct variation (that is, shows directly proportional variables).
If it does, find the constant of variation and write it in simplest form.
-8y=-5x k=
5x-y=-7 k=
-8y=-5x is a direct variation. The constant of variation, k, can be found by rewriting the equation in the form y = kx. Dividing both sides of the equation by -8 gives y = (5/8)x. Therefore, k = 5/8.
5x-y=-7 is not a direct variation. The variables x and y are not directly proportional in this equation.