To answer this question, we already know that both, y and x have a proportional relationship. We know that if this is the case, we have:
Then, we have that the ratio between both variables is constant, and it is k.
For the case in the question, we have that:
• y = -12
,
• x = 3
Then, we have:
Therefore, the value for k = -4 (in this case).
Then, the equation that represents this relationship is:
Thus
In summary, therefore, we have that the equation that represents this relationship can be written as: