Questions: Honors Algebra Il: Section 3
IXL: Solve a System of Equation:
IXL - Solve a system of equ
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Level M > E. 12 Solve system of equations in three variables using substitution X 8 H
Solve the system of equations by substitution.
-x + 3y + 2z = -4
x - y + 3z = -10
x = -6
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Transcript text: Honors Algebra Il: Section 3 |
IXL: Solve a System of Equation:
IXL - Solve a system of equ
ixl.com/math/level-m/solve-a-system-of-equations-in-three-variables-using-substitutic
$\square$
My IXL
Learning
Level M > E. 12 Solve \& system of equations in three variables using substitution X 8 H
Solve the system of equations by substitution.
\[
\begin{array}{l}
-x+3 y+2 z=-4 \\
x-y+3 z=-10 \\
x=-6
\end{array}
\]
$\square$
$\square$
,
$\square$
Submit
Work it
Not feeling ready ye
Solve a system of equations using any method
Type here to search
Solution
Solution Steps
To solve the system of equations using substitution, we can follow these steps:
Substitute the value of \( x \) from the third equation into the first and second equations.
Solve the resulting two-variable system of equations for \( y \) and \( z \).
Use the values of \( y \) and \( z \) to find \( x \).
Solution Approach
Substitute \( x = -6 \) into the first and second equations.
Solve the resulting equations for \( y \) and \( z \).
Use the values of \( y \) and \( z \) to find \( x \).
Step 1: Substitute \( x \)
We start with the system of equations:
\[
\begin{align_}
-x + 3y + 2z &= -4 \quad (1) \\
x - y + 3z &= -10 \quad (2) \\
x &= -6 \quad (3)
\end{align_}
\]
Substituting \( x = -6 \) into equations (1) and (2), we get:
\[
\begin{align*}
3y + 2z + 6 &= -4 \quad \Rightarrow \quad 3y + 2z = -10 \quad (4) \\
Now we solve the system of equations (4) and (5):
\[
\begin{align_}
3y + 2z &= -10 \quad (4) \\
-y + 3z &= -16 \quad (5)
\end{align_}
\]
From equation (5), we can express \( y \) in terms of \( z \):
\[
y = 3z + 16
\]
Substituting this expression for \( y \) into equation (4):
\[
3(3z + 16) + 2z = -10
\]
This simplifies to:
\[
9z + 48 + 2z = -10 \quad \Rightarrow \quad 11z + 48 = -10 \quad \Rightarrow \quad 11z = -58 \quad \Rightarrow \quad z = -\frac{58}{11}
\]
Step 3: Find \( y \)
Now substituting \( z = -\frac{58}{11} \) back into the expression for \( y \):
\[
y = 3\left(-\frac{58}{11}\right) + 16 = -\frac{174}{11} + \frac{176}{11} = \frac{2}{11}
\]
Final Answer
Thus, the solutions for the variables are:
\[
x = -6, \quad y = \frac{2}{11}, \quad z = -\frac{58}{11}
\]
The final boxed answer is:
\[
\boxed{x = -6, \, y = \frac{2}{11}, \, z = -\frac{58}{11}}
\]