## Elementary Linear Algebra 7th Edition

Published by Cengage Learning

# Chapter 1 - Systems of Linear Equations - 1.1 Introduction to Systems of Linear Equations - 1.1 Exercises - Page 10: 34

#### Answer

y= -0.5 x= $\frac{1}{3}$

#### Work Step by Step

step 1: Find a common factor between one of the variables x or y. In this case we can multiply $\frac{1}{2}$ by 18 to make the x variable equal in both equations. 9x - 4y = 5 $\frac{1}{2} + \frac{1}{3}$ = 0 9x - 4y = 5 $(18) \frac{1}{2} + \frac{1}{3}$ = 0 Step 2: X values cancels out. As y values are opposites you have to take them away. 9x - 4y = 5 9x + 6y = 0 -10y = 5 step 3: rearrange so you get the y value on its own. -y =$\frac{3}{9}$ y = - $\frac{1}{2}$ Step 4: Use your y answer to solve one of the equations by substituting y by -$\frac{1}{2}$ 9x - 4 (- $\frac{1}{2}$) = 5 Step 5: rearrange the equation so x is left by its own. 9x -4 (-0.50) = 5 9x + 2 = 5 9x = 5 -2 9x = 3 x =$\frac{3}{9}$ x = $\frac{1}{3}$

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.