Math Problem Statement

Consider the following system of linear equations: 2x1+2x2+6x3 = −14 −x1+4x2+2x3 = −13 3x1+7x3 = −10

Let A be the coefficient matrix and X the solution matrix to the system. Solve the system by first computing A−1 and then using it to find X.

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Solution

To solve the given system of linear equations using matrix inversion, let's proceed with the following steps:

Step 1: Write the System in Matrix Form

The given system is:

2x1+2x2+6x3=142x_1 + 2x_2 + 6x_3 = -14 x1+4x2+2x3=13-x_1 + 4x_2 + 2x_3 = -13 3x1+0x2+7x3=103x_1 + 0x_2 + 7x_3 = -10

We can write this system in matrix form as AX=BA \cdot X = B, where AA is the coefficient matrix, XX is the variable matrix, and BB is the constant matrix.

A=[226142307],X=[x1x2x3],B=[141310]A = \begin{bmatrix} 2 & 2 & 6 \\ -1 & 4 & 2 \\ 3 & 0 & 7 \end{bmatrix}, \quad X = \begin{bmatrix} x_1 \\ x_2 \\ x_3 \end{bmatrix}, \quad B = \begin{bmatrix} -14 \\ -13 \\ -10 \end{bmatrix}

Step 2: Find the Inverse of Matrix A (A1A^{-1})

To solve for XX, we need to compute the inverse of AA, if it exists.

Let's compute A1A^{-1}.

The inverse of matrix AA is:

A1=[2.81.42.01.30.41.01.20.61.0]A^{-1} = \begin{bmatrix} 2.8 & -1.4 & -2.0 \\ 1.3 & -0.4 & -1.0 \\ -1.2 & 0.6 & 1.0 \end{bmatrix}

Step 3: Solve for Matrix XX

To find the solution matrix XX, we use the equation:

X=A1BX = A^{-1} \cdot B

Let's calculate XX.The solution matrix XX is:

X=[131]X = \begin{bmatrix} -1 \\ -3 \\ -1 \end{bmatrix}

Thus, the solutions are: x1=1,x2=3,x3=1x_1 = -1, \quad x_2 = -3, \quad x_3 = -1

Would you like more details or have any questions about this process?

Related Questions:

  1. How can we determine if a matrix is invertible before attempting to find its inverse?
  2. What is the significance of using matrix inversion to solve a system of linear equations?
  3. Can you solve the system using other methods, such as Gaussian elimination?
  4. What happens if the determinant of the matrix AA is zero?
  5. How can we interpret the solution geometrically if there are infinitely many solutions?

Tip: Always verify if a matrix is invertible by checking if its determinant is non-zero before attempting to compute its inverse.

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Math Problem Analysis

Mathematical Concepts

Linear Algebra
Matrix Inversion
Systems of Linear Equations

Formulas

Matrix form of system: A * X = B
Inverse of a matrix: A^(-1)
Solution to system: X = A^(-1) * B

Theorems

Inverse Matrix Theorem
Properties of Matrices

Suitable Grade Level

Undergraduate Level or Advanced High School (Grades 11-12)