1. **State the problem:** Solve the system of equations using the substitution method:
$$\begin{cases} 4x - 3y + z = -10 \\ 2x + y + 3z = 0 \\ -x + 2y - 5z = 17 \end{cases}$$
2. **Choose one equation to express one variable in terms of the others.** From the first equation:
$$4x - 3y + z = -10 \implies z = -10 - 4x + 3y$$
3. **Substitute this expression for $z$ into the other two equations:**
Second equation:
$$2x + y + 3(-10 - 4x + 3y) = 0$$
$$2x + y - 30 - 12x + 9y = 0$$
$$\cancel{2x} - 12x + \cancel{y} + 9y - 30 = 0$$
$$-10x + 10y - 30 = 0$$
$$-10x + 10y = 30$$
$$-\cancel{10}x + \cancel{10}y = \cancel{10}3$$
$$-x + y = 3$$
Fourth step: Third equation:
$$-x + 2y - 5(-10 - 4x + 3y) = 17$$
$$-x + 2y + 50 + 20x - 15y = 17$$
$$-x + 20x + 2y - 15y + 50 = 17$$
$$19x - 13y + 50 = 17$$
$$19x - 13y = 17 - 50$$
$$19x - 13y = -33$$
4. **Now solve the simpler system:**
$$\begin{cases} -x + y = 3 \\ 19x - 13y = -33 \end{cases}$$
From the first equation:
$$y = x + 3$$
Substitute into the second:
$$19x - 13(x + 3) = -33$$
$$19x - 13x - 39 = -33$$
$$6x - 39 = -33$$
$$6x = -33 + 39$$
$$6x = 6$$
$$x = \frac{6}{6} = 1$$
5. **Find $y$:**
$$y = 1 + 3 = 4$$
6. **Find $z$ using the expression from step 2:**
$$z = -10 - 4(1) + 3(4) = -10 - 4 + 12 = -2$$
**Final answer:**
$$\boxed{(x, y, z) = (1, 4, -2)}$$
System Substitution 78C83C
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.