how do i tell wheater x and y show direct variation. Explain your reasoning. If so, find k. And the problem is 8=xy

Question

I need answers on my math homework. I got half of it done i need help on the other half.

Answer 1

y varies directly as x if y = kx for some constant, k.  In other words, y/x is constant.  

 

y varies inversely as x if y = k/x for some constant, k.  In other words, xy is constant.

 

The equation xy = 8 is an example of inverse variation, not direct variation.