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: 54

Answer

$(\frac{22}{5},\frac{24}{25},\frac{66}{25})$

Work Step by Step

Step 1. Based on the Cramer’s Rule, with the given equations, we can define the following determinants: $\begin{array}( \\|D|= \\ \\ \end{array} \begin{vmatrix}2 &-5&0\\1&1&-1\\3&0&5 \end{vmatrix}, \begin{array}( \\|D_x|= \\ \\ \end{array} \begin{vmatrix}4 &-5&0\\8&1&-1\\0&0&5 \end{vmatrix}, \begin{array}( \\|D_y|= \\ \\ \end{array} \begin{vmatrix}2 &4&0\\1&8&-1\\3&0&5 \end{vmatrix}, \begin{array}( \\|D_z|= \\ \\ \end{array} \begin{vmatrix}2 &-5&4\\1&1&8\\3&0&0 \end{vmatrix}$ Step 2. Evaluate the above determinants: $|D|=(3)(5-0)+(5)(2+5)=50$ (row3 expansion), $|D_x|=(5)(4+40)=220$ (row3 expansion), $|D_y|=(3)(-4-0)+(5)(16-4)=48$ (row3 expansion), $|D_z|=(3)(-40-4)=132$ (row3 expansion), Step 3. Find the solutions as: $x=\frac{|D_x|}{|D|}=\frac{22}{5}$, $y=\frac{|D_y|}{|D|}=\frac{24}{25}$, $z=\frac{|D_z|}{|D|}=\frac{66}{25}$
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.