Amir is buying tickets for the $120 million lottery. If he buys tickets with his brother, then they will split the money equally. But he is also considering buying tickets with his brother's four friends, and they will each get million. Is this an example of direct, inverse, or joint variation?

The heir to the austrian throne, archduke franz ferdinand was gunned down by a young serbian terrorist. germany urged austria to declare war on serbia. russia mobilized against austria, then germany mobilized against russia. france and britain mobilized against germany. then young men such as adolf hitler volunteered in the war.

I'm pretty sure it's, y=2x+16. 

Use that as an example to solve it