Answer
$y$ is a function of $x$.
Work Step by Step
$xy+2y=1$
$y(x+2)=1$
$y=\frac{1}{x+2}$
Since one $x$ value will give you one $y$ value, $y$ is a function of $x$.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.