Answer: 
Step-by-step explanation:
By definition, a direct varition is expressed as following:

Then, <em>y </em>is directly proportional to <em>x </em>and <em>k</em> is the constant of variation.
Therefore, given the direct variation:

You must solve for the variable <em>y </em>as you can see below:

Therefore, as you can see, the constant of variation is the following:
