# Make the given changes in the indicated examples of this section and then solve the resulting problems. In Example 4, change x to 2x in the second equation and then solve the system of equations. Data from Example 4 Use the method of addition or subtraction to solve the following system of equations. 3x 2y = 4 x +

Chapter 5, Exercises 5.3 #3

Make the given changes in the indicated examples of this section and then solve the resulting problems.

In Example 4, change x to 2x in the second equation and then solve the system of equations.

Data from Example 4

Use the method of addition or subtraction to solve the following system of equations.

3x − 2y = 4

x + 3y = 2

Looking at the coefficients of x and y, we see that we must multiply the second equation by 3 to make the coefficients of x the same. To make the coefficients of y numerically the same, we must multiply the first equation by 3 and the second equation by 2. Thus, the best method is to multiply the second equation by 3 and eliminate x. CAUTION Be careful to multiply the terms on both sides: a common error is to forget to multiply the value on the right. ■ After multiplying, the coefficients of x have the same sign. Therefore, we subtract terms of the second equation from those of the first equation: In order to find the value of x, substitute y = 2/11 into one of the original equations. Choosing the second equation (its form is somewhat simpler), we have Therefore, the solution is x = 16/11, y = 2/11. Substituting these values into both of the original equations shows that the solution checks.

Related Book For ## Basic Technical Mathematics

12th Edition

Authors: Allyn J. Washington, Richard Evans

ISBN: 9780137529896