Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 10 - Section 10.6 - Determinants and Cramer's Rule - 10.6 Exercises - Page 743: 53

Answer

$(\frac{189}{29},-\frac{108}{29},\frac{88}{29})$

Work Step by Step

Step 1. Based on the Cramer’s Rule, with the given equations, we can define the following determinants: $\begin{array}( \\|D|= \\ \\ \end{array} \begin{vmatrix}0 &3&5\\2&0&-1\\4&7&0 \end{vmatrix}, \begin{array}( \\|D_x|= \\ \\ \end{array} \begin{vmatrix} 4&3&5\\10&0&-1\\0&7&0\end{vmatrix}, \begin{array}( \\|D_y|= \\ \\ \end{array} \begin{vmatrix}0 &4&5\\2&10&-1\\4&0&0\end{vmatrix}, \begin{array}( \\|D_z|= \\ \\ \end{array} \begin{vmatrix}0 &3&4\\2&0&10\\4&7&0\end{vmatrix}$ Step 2. Evaluate the above determinants: $|D|=(4)(-3-0)-(7)(0-10)=58$ (row3 expansion), $|D_x|=-(7)(-4-50)=378$ ((row3 expansion), $|D_y|=(4)(-4-50)=-216$ ((row3 expansion), $|D_z|=(4)(30-0)-(7)(0-8)=176$ ((row3 expansion), Step 3. Find the solutions as: $x=\frac{|D_x|}{|D|}=\frac{189}{29}$, $y=\frac{|D_y|}{|D|}=-\frac{108}{29}$, $z=\frac{|D_z|}{|D|}=\frac{88}{29}$
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.