Answer:
150 + 4x = 330
4x = 180
x = 45
Step-by-step explanation:
An equation of direct variation is something like
![y=kx](https://tex.z-dn.net/?f=y%3Dkx)
If we have a value for x and y, we simply have to plug these values and see which constant k suits our case:
![y=kx \implies -17=-10k \implies k = \dfrac{-17}{-10}=\dfrac{17}{10}](https://tex.z-dn.net/?f=y%3Dkx%20%5Cimplies%20-17%3D-10k%20%5Cimplies%20k%20%3D%20%5Cdfrac%7B-17%7D%7B-10%7D%3D%5Cdfrac%7B17%7D%7B10%7D)
So, the relation
![y=\dfrac{17}{10}x](https://tex.z-dn.net/?f=y%3D%5Cdfrac%7B17%7D%7B10%7Dx)
is a relation of direct variation and it includes the point (-10,-17).