Algebra 2 (1st Edition)

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

Chapter 3 Linear Systems and Matrices - 3.7 Evaluate Determinants and Apply Cramer's Rule - 3.7 Exercises - Skill Practice - Page 208: 29

Answer

$x=-4,y=3$

Work Step by Step

We know that for a matrix \[ \left[\begin{array}{rr} a & b \\ c &d \\ \end{array} \right] \] the determinant is $D=ad-bc.$ Thus the determinant of the coefficient matrix is: $D=3\cdot2-5\cdot(-1)=6+5=11.$ Then applying Cramer's Rule: $x=\frac{\begin{vmatrix} 3 & 5\\ 10 & 2 \\ \end{vmatrix}}{1}=\frac{3\cdot2-5\cdot10}{11}=\frac{-44}{11}=-4$ $y=\frac{\begin{vmatrix} 3 & 3 \\ -1 & 10 \\ \end{vmatrix}}{1}=\frac{3\cdot10-3\cdot-1}{11}=\frac{33}{1}=3$ Thus $x=-4,y=3$
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.