Show by implicit differentiation that, for any constants a, b, and c, the equation ax+by=c defines a solution to the DE of dy/dx=-a/b. I know that it's

Show by implicit differentiation that, for any constants a, b, and c, the equation ax+by=c defines a solution to the DE of dy/dx=-a/b.  I know that it's similar to the chain rule and that you need to isolate the dy/dx, but how do you get rid of the x if you are finding the derivate in terms of y and the answer is in terms of a and b?