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:
$$2x + y + 3(-10 - 4x + 3y) = 0$$
Simplify:
$$2x + y - 30 - 12x + 9y = 0$$
Combine like terms:
$$-10x + 10y - 30 = 0$$
Add 30 to both sides:
$$-10x + 10y = 30$$
Divide both sides by 10:
$$\cancel{-10}x + \cancel{10}y = \cancel{30}3 \implies -x + y = 3$$
Fourth step: Third equation:
$$-x + 2y - 5(-10 - 4x + 3y) = 17$$
Simplify:
$$-x + 2y + 50 + 20x - 15y = 17$$
Combine like terms:
$$19x - 13y + 50 = 17$$
Subtract 50 from both sides:
$$19x - 13y = -33$$
5. **Now solve the system:**
$$\begin{cases} -x + y = 3 \\ 19x - 13y = -33 \end{cases}$$
From the first equation:
$$y = x + 3$$
Substitute into the second:
$$19x - 13(x + 3) = -33$$
Simplify:
$$19x - 13x - 39 = -33$$
Combine like terms:
$$6x - 39 = -33$$
Add 39 to both sides:
$$6x = 6$$
Divide both sides by 6:
$$\cancel{6}x = \cancel{6}1 \implies x = 1$$
6. **Find $y$:**
$$y = 1 + 3 = 4$$
7. **Find $z$ using the expression from step 2:**
$$z = -10 - 4(1) + 3(4) = -10 - 4 + 12 = -2$$
**Final solution:**
$$\boxed{(x, y, z) = (1, 4, -2)}$$
Substitution System 07Ebaa
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