Algebra 2 (1st Edition)

Published by McDougal Littell
ISBN 10: 0618595414
ISBN 13: 978-0-61859-541-9

Chapter 3 Linear Systems and Matrices - 3.4 Solve Systems of Linear Equations in Three Variables - 3.4 Exercises - Skill Practice - Page 183: 31

Answer

$(0,-2,6)$ is a solution of the system.

Work Step by Step

Use elimination for the first and the third equation: $-x + 5y- z=-16$ $x + y -z =-8$ ________________________ $6y-2z=-24$ (1) Then continue to use elimination for the first and second equation: $x + y -z =-8$ $2x + 3y +4z= 18$ Multiply both sides of the first equation by $-2$ $-2x -2y +2z =16$ $2x + 3y +4z= 18$ _______________________ $y+6z=34$ (2) From (1) and (2): $6y-2z=-24$ $y+6z=34$ Multiply both sides of the first equation by $3$: $18y-6z=-72$ $y+6z=34$ ___________________ $19y=-38$ $y=-2$ Solve for z: $-2+6z=34$ $z=6$ Solve for x: $x+(-2)-6=-8$ $x=0$ $(0,-2,6)$ is a solution of the system.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

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.