In solving a system of equations using row operations, the goal is to transform the corresponding matrix into row echelon form. This form is characterized by having all leading coefficients (the first non-zero number from the left in a row) as 1, with all entries below these leading 1s being 0. The entries above the leading 1s can be any number.
To begin, convert the system of equations into an augmented matrix by extracting the coefficients of the variables. For example, if the system is represented as:
\[\begin{align*}1x + 3y + 4z &= 2 \\2x + 5y + 7z &= 9 \\4x + 8y + 10z &= 14\end{align*}\]
the corresponding augmented matrix would be:
\[\begin{bmatrix}1 & 3 & 4 & | & 2 \\2 & 5 & 7 & | & 9 \\4 & 8 & 10 & | & 14\end{bmatrix}\]
Next, apply row operations to achieve the desired form. The operations include:
- Swapping two rows
- Multiplying a row by a non-zero scalar
- Adding or subtracting a multiple of one row to another row
For instance, to eliminate the entries below the leading 1 in the first column, you can manipulate the second and third rows. If you want to make the entry in the second row, first column a zero, you can add a multiple of the first row to the second row. This process continues until all entries below the leading 1s are zero.
Once the matrix is in row echelon form, the next step is to back substitute to find the values of the variables. For example, if the final matrix looks like this:
\[\begin{bmatrix}1 & 3 & 4 & | & 2 \\0 & 1 & 1 & | & -5 \\0 & 0 & 1 & | & 7\end{bmatrix}\]
From the last row, you can directly read off that \( z = 7 \). Substitute \( z \) back into the second row to find \( y \):
\[y + z = -5 \implies y + 7 = -5 \implies y = -12\end{p}
Finally, substitute both \( y \) and \( z \) back into the first equation to solve for \( x \):
\[x + 3(-12) + 4(7) = 2 \implies x - 36 + 28 = 2 \implies x = 10\end{p}
Thus, the solution to the system of equations is \( x = 10 \), \( y = -12 \), and \( z = 7 \). This methodical approach using row operations allows for systematic solving of linear systems, ensuring clarity and accuracy in the results.