For this case we have to by definition, if "y" varies directly with "x" then it is true that:
![y = kx](https://tex.z-dn.net/?f=y%20%3D%20kx)
Where:
k: Is the constant of proportionality
We find the constant "k" according to the given data:
![14 = k (-4)\\k = - \frac {14} {4} = -\frac {7} {2}](https://tex.z-dn.net/?f=14%20%3D%20k%20%28-4%29%5C%5Ck%20%3D%20-%20%5Cfrac%20%7B14%7D%20%7B4%7D%20%3D%20-%5Cfrac%20%7B7%7D%20%7B2%7D)
Thus, the constant of proportionality is ![- \frac {7} {2}.](https://tex.z-dn.net/?f=-%20%5Cfrac%20%7B7%7D%20%7B2%7D.)
Now, we find the value of "y" when ![x = -6:](https://tex.z-dn.net/?f=x%20%3D%20-6%3A)
![y = - \frac {7} {2} (- 6)\\y = \frac {42} {2}\\y = 21](https://tex.z-dn.net/?f=y%20%3D%20-%20%5Cfrac%20%7B7%7D%20%7B2%7D%20%28-%206%29%5C%5Cy%20%3D%20%5Cfrac%20%7B42%7D%20%7B2%7D%5C%5Cy%20%3D%2021)
Thus, when
, the value of y is 21.
ANswer:
![y = 21](https://tex.z-dn.net/?f=y%20%3D%2021)