Question

y and x have a proportional relationship, and y= -12 when x =3 . what equation represents this relationship?

Answer 1

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:

$\frac{y}{x}=k\Rightarrow y=kx$

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:

$\frac{y}{x}=-\frac{12}{3}=-4\Rightarrow k=-4$

Therefore, the value for k = -4 (in this case).

Then, the equation that represents this relationship is:

$\frac{y}{x}=k\Rightarrow y=kx$

Thus

$\frac{y}{x}=-4\Rightarrow y=-4x$

In summary, therefore, we have that the equation that represents this relationship can be written as:

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