## Algebra 2 (1st Edition)

Published by McDougal Littell

# Chapter 8 Rational Functions - 8.1 Model Inverse and Joint Variation - Guided Practice for Examples 5 and 6 - Page 554: 11

See below.

#### Work Step by Step

The general equation for joint variation is: $z=axy$ where $a$ is some constant. Then plugging in the given values for $z,x,y$ we get: $18=a(-2)(6)=-12a\\a=-1.5$. Thus the model is: $z=-1.5xy$. Then plugging in $x=-2,y=5$: $z=-1.5(-2)(5)=15$

After 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.