When y varies directly as x , we write it mathematically as
y =Kx, where K is the constant of variation. In a direct variation, x and y both behave in the same manner, when x increases- y also increses. when x decreases, y also decreases.
When y varies indirectly as x we write y = K/x, K is the constant of variation. Here , when x increases y decreases ans vice versa.
