Internet Audience At the end of a certain year, the four companies with the largest number of home Internet users in the United States were Microsoft, Time Warner, Yahoo, and Google, with a combined audience of 284 million users. Taking \textit{x} to be the Microsoft audience in millions, \textit{y} the Time Warner audience in millions, \textit{z} the Yahoo audience in millions, and \textit{u} the Google audience in millions, it was observed that
$z - u = 3(x - y) + 20$
$x + y = 50 + z + u$
$x - y + z - u = 56$.
How large was the audience of each of the four companies at the end of that year?
Microsoft
Time Warner
Yahoo
Google
