Tell whether the equation represents direct variation. If it does find the constant of direct variation. -12 + 8y +12 = 7x.

Given:

The equation is

To find:

The constant of direct variation if the given equation represents direct variation.

Solution:

If y is directly proportional to x, then

           ...(i)

Where, k is the constant of proportionality.

We have,

         ...(ii)

At x=0,

The equation (ii) passes through (0,0). So, it represents a proportional relationship.

On comparing (i) and (ii), we get

Therefore, the constant of proportionality is .