Math Problem Statement

Test for consistency of the following system of equations 2x - 3y + 5z = 1, 3x + y - z = 2, x + 4y - 6z = 1 and, if consistent, solve the system.

Solution

The problem asks us to test for the consistency of the given system of equations and, if consistent, solve it. Let's go step by step:

Given System of Equations:

  1. 2x3y+5z=12x - 3y + 5z = 1
  2. 3x+yz=23x + y - z = 2
  3. x+4y6z=1x + 4y - 6z = 1

Testing for Consistency:

To test for consistency, we use the augmented matrix of the system of equations. The goal is to check if the system has solutions (consistent) or no solutions (inconsistent).

Step 1: Write the augmented matrix.

2 & -3 & 5 & 1 \\ 3 & 1 & -1 & 2 \\ 1 & 4 & -6 & 1 \end{bmatrix}$$ #### Step 2: Perform Gaussian elimination. 1. **Normalize Row 1 (R1):** Divide Row 1 by $$2$$: $$R1 \to \frac{R1}{2}: \begin{bmatrix} 1 & -3/2 & 5/2 & 1/2 \\ 3 & 1 & -1 & 2 \\ 1 & 4 & -6 & 1 \end{bmatrix}.$$ 2. **Eliminate the first variable (x) from R2 and R3:** $$R2 \to R2 - 3R1,\quad R3 \to R3 - R1$$ After performing these row operations, the matrix becomes: $$\begin{bmatrix} 1 & -3/2 & 5/2 & 1/2 \\ 0 & 11/2 & -19/2 & 1/2 \\ 0 & 11/2 & -17/2 & 1/2 \end{bmatrix}.$$ 3. **Eliminate the second variable (y) from R3:** Subtract $$R2$$ from $$R3$$: $$R3 \to R3 - R2.$$ This results in: $$\begin{bmatrix} 1 & -3/2 & 5/2 & 1/2 \\ 0 & 11/2 & -19/2 & 1/2 \\ 0 & 0 & 1 & 0 \end{bmatrix}.$$ --- ### Solution of the System: From the matrix, the equations can now be rewritten as: 1. $$z = t$$ (free parameter) 2. $$\frac{11}{2}y - \frac{19}{2}z = \frac{1}{2}$$ 3. $$x - \frac{3}{2}y + \frac{5}{2}z = \frac{1}{2}$$ #### Solving for $$y$$ and $$x$$: 1. From the second equation: $$11y - 19z = 1 \implies y = \frac{1 + 19z}{11}.$$ 2. From the first equation: $$x - \frac{3}{2}y + \frac{5}{2}z = \frac{1}{2}.$$ Substituting $$y = \frac{1 + 19z}{11}$$: $$x = \frac{7}{11} - \frac{2z}{11}.$$ --- ### Final Parametric Solution: The solution is: $$x = \frac{7}{11} - \frac{2t}{11},\quad y = \frac{1}{11} + \frac{17t}{11},\quad z = t,$$ where $$t$$ is a free parameter. The system is **consistent**. --- ### Do you want further clarification or details? Let me know! Here are 5 related questions for exploration: 1. What is the difference between consistent and inconsistent systems of equations? 2. How is Gaussian elimination used to solve linear systems? 3. What does it mean when a system has infinitely many solutions? 4. How can we verify the solution of this system of equations? 5. How can parametric solutions be visualized in three dimensions? **Tip:** When solving systems with parameters, always interpret the solution geometrically to understand the nature of the solutions!

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Math Problem Analysis

Mathematical Concepts

Systems of Linear Equations
Matrix Algebra
Gaussian Elimination

Formulas

Gaussian elimination steps for solving linear systems
Parametric representation of solutions

Theorems

Consistency of linear systems
Row reduction in matrices

Suitable Grade Level

Undergraduate (Linear Algebra Level)