Questions: Solve the system.
-3x-y=6
y-2z=1
x-4y+z=9
Select the correct choice below and fill in any answer boxes within your choice.
A. There is one solution. The solution set is ( , , ) (Simplify your answers.)
B. There are infinitely many solutions.
C. There is no solution.
Transcript text: Solve the system.
\[
\begin{array}{r}
-3 x-y=6 \\
y-2 z=1 \\
x-4 y+z=9
\]
Select the correct choice below and fill in any answer boxes within your choice.
A. There is one solution. The solution set is $\{($ $\square$
$\square$ , $\square$ ) \} (Simplify your answers.)
B. There are infinitely many solutions.
C. There is no solution.
Solution
Solution Steps
Step 1: Formulate the System of Equations
We start with the given system of equations:
\[
\begin{array}{r}
-3x - y = 6 \\
y - 2z = 1 \\
x - 4y + z = 9
\end{array}
\]
Step 2: Represent the System in Matrix Form
We can represent this system in the augmented matrix form \( [A | b] \):
\[
\left[ A | b \right] = \left[ \begin{array}{ccc|c}
-3 & -1 & 0 & 6 \\
0 & 1 & -2 & 1 \\
1 & -4 & 1 & 9 \\
\end{array} \right]
\]
Step 3: Perform Gaussian Elimination
Through Gaussian elimination, we transform the matrix step by step until we reach the reduced row echelon form:
\[
\left[ A | b \right] = \left[ \begin{array}{ccc|c}
1 & 0 & 0 & -1 \\
0 & 1 & 0 & -3 \\
0 & 0 & 1 & -2 \\
\end{array} \right]
\]
Step 4: Extract the Solutions
From the final matrix, we can read off the solutions for the variables:
\[
x = -1, \quad y = -3, \quad z = -2
\]
Final Answer
The solution set is \(\{(x, y, z) = (-1, -3, -2)\}\). Therefore, the answer is A.
\[
\boxed{(x, y, z) = (-1, -3, -2)}
\]