Gauss Elimination
1. **Stating the problem:** We have a system of linear equations:
$$
ax + by + cz = j \\
dx + ey + fz = k \\
gx + hy + iz = l
$$
We want to find expressions for $z$, $y$, and $x$ using Gauss Elimination.
2. **Eliminate variables to find $z$: **
- The coefficients form matrices that we manipulate. Gauss elimination reduces the system stepwise.
3. **Deriving $z$: **
Given the relation:
$$
z = \frac{(bg - ah)(dj - ak) - (bd - ae)(gj - al)}{(bg - ah)(cd - af) - (bd - ae)(cg - ai)}
$$
This comes from applying elimination on the coefficients and constants, solving the resulting simplified equations for $z$.
4. **Deriving $y$: **
Using $z$ above, substitute in the simplified second equation to isolate $y$:
$$
y = \frac{1}{bd - ae}\left[(dj - ak) - z(cd - af)\right]
$$
This expression shows the direct dependency of $y$ on $z$ and the constants.
5. **Deriving $x$: **
Finally, from the first equation, express $x$ in terms of $y$ and $z$:
$$
x = \frac{1}{a}[j - yb - zc]
$$
This completes the solution using Gaussian elimination.
All steps use the linear manipulation of equations and substitution arriving at these formulas.