Math Problem Statement

Which of the following augmented matrices are inconsistent? Select ALL that apply.

⎡⎣⎢⎢⎢⎢25006000008000−88−56−4−6⎤⎦⎥⎥⎥⎥

⎡⎣⎢⎢⎢⎢4−80008007300⎤⎦⎥⎥⎥⎥

⎡⎣⎢⎢⎢⎢80164−70−1402060⎤⎦⎥⎥⎥⎥

⎡⎣⎢⎢⎢⎢800000500000000−8−9445⎤⎦⎥⎥⎥⎥

Solution

To determine which of these augmented matrices are inconsistent, we need to look for rows that represent contradictions, such as a row where all coefficients of the variables are zero but the last entry (constant) is nonzero. This indicates no solution exists.

Let’s analyze each augmented matrix:

Matrix 1:

2 & 5 & 0 & 0 & 6 \\ 0 & 0 & 0 & 0 & 8 \\ 0 & 0 & 0 & -8 & -6 \\ -4 & -6 & 0 & 0 & 0 \\ \end{pmatrix}$$ - Row 2: $$[ 0 \, 0 \, 0 \, 0 | 8 ]$$ represents $$0 = 8$$, which is a contradiction. This row indicates that the system has no solution. - **Conclusion:** This matrix is **inconsistent**. ### Matrix 2: $$\begin{pmatrix} 4 & -8 & 0 & 0 & 0 \\ 0 & 8 & 0 & 7 & 3 \\ 0 & 0 & 7 & 0 & 0 \\ \end{pmatrix}$$ - There is no row representing a contradiction. The system seems solvable. - **Conclusion:** This matrix is **consistent**. ### Matrix 3: $$\begin{pmatrix} 8 & 0 & 1 & 6 \\ 4 & -7 & 0 & -14 \\ 0 & 20 & 6 & 0 \\ \end{pmatrix}$$ - No row represents a contradiction. - **Conclusion:** This matrix is **consistent**. ### Matrix 4: $$\begin{pmatrix} 8 & 0 & 0 & 0 & 5 \\ 0 & 0 & 0 & 0 & 0 \\ 0 & -8 & -9 & 4 & 5 \\ \end{pmatrix}$$ - Row 2: $$[ 0 \, 0 \, 0 \, 0 | 0 ]$$ represents $$0 = 0$$, which is true but doesn't affect consistency. - There are no contradictions in the other rows, so no inconsistency. - **Conclusion:** This matrix is **consistent**. ### Final Answer: The **inconsistent matrix** is: - Matrix 1. Would you like any further explanation or help with similar problems? --- ### Further Questions: 1. How do you perform Gaussian elimination on augmented matrices? 2. Can an inconsistent system have a unique solution in any case? 3. How do you identify the rank of a matrix? 4. What does it mean for a system to be consistent or inconsistent in terms of linear dependence? 5. Can a system of equations have more than one solution even if it is consistent? ### Tip: If you encounter an augmented matrix with a row that looks like $$[0 \, 0 \, 0 | b]$$ where $$b \neq 0$$, the system is automatically inconsistent because it implies a false statement like $$0 = b$$.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Linear Algebra
Systems of Linear Equations
Augmented Matrices
Matrix Inconsistency

Formulas

Row echelon form
Contradictory row identification

Theorems

Rank of a matrix
Consistency of a system of linear equations

Suitable Grade Level

Grades 11-12