Math Problem Statement

Fill in the blanks of the resulting matrix after each given row operation is performed on the matrix: Initial matrix: \[ \begin{bmatrix} 4 & -3 & 6 \\ -4 & 5 & -4 \end{bmatrix} \] 1. Apply \(-4R_1\) to the first row. 2. Apply \(R_2 + 3R_1\) to the second row. 3. Apply \(R_1 - 4R_2\) to the first row.

Solution

Let's go through each row operation shown in the matrix, step-by-step, to complete the missing entries.

The matrix initially given is:

[436454]\begin{bmatrix} 4 & -3 & 6 \\ -4 & 5 & -4 \end{bmatrix}

Step 1: Applying 4R1-4R_1

The operation 4R1-4R_1 means we multiply each element in the first row R1R_1 by 4-4:

  1. For the element in the first row and first column: 4×4=164 \times -4 = -16
  2. For the element in the first row and second column: 3×4=12-3 \times -4 = 12
  3. For the element in the first row and third column: 6×4=246 \times -4 = -24

After performing this operation, the new matrix becomes:

[161224454]\begin{bmatrix} -16 & 12 & -24 \\ -4 & 5 & -4 \end{bmatrix}

Step 2: Applying R2+3R1R_2 + 3R_1

For this step, we add 33 times the first row R1R_1 to the second row R2R_2:

  1. For the element in the second row and first column: 4+3×4=4+12=8-4 + 3 \times 4 = -4 + 12 = 8
  2. For the element in the second row and second column: 5+3×3=59=45 + 3 \times -3 = 5 - 9 = -4
  3. For the element in the second row and third column: 4+3×6=4+18=14-4 + 3 \times 6 = -4 + 18 = 14

After this operation, the matrix becomes:

[4368414]\begin{bmatrix} 4 & -3 & 6 \\ 8 & -4 & 14 \end{bmatrix}

Step 3: Applying R14R2R_1 - 4R_2

In this operation, we subtract 44 times the second row R2R_2 from the first row R1R_1:

  1. For the element in the first row and first column: 44×8=432=284 - 4 \times 8 = 4 - 32 = -28
  2. For the element in the first row and second column: 34×4=3+16=13-3 - 4 \times -4 = -3 + 16 = 13
  3. For the element in the first row and third column: 64×14=656=506 - 4 \times 14 = 6 - 56 = -50

After this operation, the matrix becomes:

[2813508414]\begin{bmatrix} -28 & 13 & -50 \\ 8 & -4 & 14 \end{bmatrix}

Summary of the Results

The resulting matrices after each row operation are:

  1. After 4R1-4R_1: [161224454]\begin{bmatrix} -16 & 12 & -24 \\ -4 & 5 & -4 \end{bmatrix}

  2. After R2+3R1R_2 + 3R_1: [4368414]\begin{bmatrix} 4 & -3 & 6 \\ 8 & -4 & 14 \end{bmatrix}

  3. After R14R2R_1 - 4R_2: [2813508414]\begin{bmatrix} -28 & 13 & -50 \\ 8 & -4 & 14 \end{bmatrix}

Would you like further explanation on any of the steps?

Relative Questions:

  1. What is the purpose of row operations in matrix transformations?
  2. How does multiplying a row by a scalar affect the determinant of the matrix?
  3. What is the significance of the identity matrix in row operations?
  4. Can matrix row operations change the rank of a matrix? Why or why not?
  5. How do row operations help in solving systems of linear equations?

Tip:

Row operations are fundamental for simplifying matrices in Gaussian elimination, which helps solve systems of linear equations efficiently.

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Math Problem Analysis

Mathematical Concepts

Matrix Operations
Row Operations
Linear Algebra

Formulas

Row Operation Formulas: R1 = R1 - k * R2, R2 = R2 + k * R1, R = k * R

Theorems

Elementary Row Operations
Matrix Transformation

Suitable Grade Level

Grades 10-12