Math Problem Statement

For the system of equations: 6x - 3y - 7z = -4, 24x + 5y + kz = 3, 9x + 4y - 3z = 5, determine the condition for consistency and find the value of k.

Solution

To solve the given system of equations and determine the condition for consistency, we need to ensure that the determinant of the coefficient matrix is non-zero. This guarantees that the system has a unique solution, making it consistent.

The system of equations provided is:

6x3y7z=46x - 3y - 7z = -4 24x+5y+kz=324x + 5y + kz = 3 9x+4y3z=59x + 4y - 3z = 5

Step 1: Coefficient Matrix

The coefficient matrix of the system is:

6 & -3 & -7 \\ 24 & 5 & k \\ 9 & 4 & -3 \end{pmatrix}$$ For the system to be consistent, the determinant of the matrix must not be zero. Let’s compute the determinant of $$A$$. $$\det(A) = \begin{vmatrix} 6 & -3 & -7 \\ 24 & 5 & k \\ 9 & 4 & -3 \end{vmatrix}$$ We can expand this determinant along the first row: $$\det(A) = 6 \begin{vmatrix} 5 & k \\ 4 & -3 \end{vmatrix} - (-3) \begin{vmatrix} 24 & k \\ 9 & -3 \end{vmatrix} + (-7) \begin{vmatrix} 24 & 5 \\ 9 & 4 \end{vmatrix}$$ Now I will compute the determinant for each 2x2 matrix. Let me calculate that for you:The determinant of the matrix $$A$$ is: $$\det(A) = -51k - 663$$ ### Step 2: Condition for Consistency For the system to be consistent, the determinant must not be equal to zero: $$-51k - 663 \neq 0$$ Solving for $$k$$, we get: $$k \neq -\frac{663}{51} = -13$$ Thus, the system will be consistent as long as $$k \neq -13$$. Would you like further clarification on any part of this solution? Here are some related questions for further exploration: 1. How do you solve a system of equations using matrix methods like Cramer's Rule? 2. What does it mean for a system of equations to be consistent or inconsistent? 3. Can you explain how to find the inverse of a matrix when the determinant is non-zero? 4. How do you solve a system of linear equations using Gaussian elimination? 5. What are the applications of determinants in linear algebra? **Tip**: Always check the determinant of a matrix when determining if a system of linear equations has a unique solution.

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Systems of Equations
Determinants

Formulas

Determinant of a 3x3 matrix
Expansion of determinant along a row
Consistency condition for systems of linear equations

Theorems

Determinants and Invertibility
System Consistency Theorem

Suitable Grade Level

Grades 11-12 or Early College Level