Use back-substitution to solve the system of linear equations.? $$\left\{ \begin{array} { c c }
x - y + 2 z & = 22 \
3 y - 8 z & = - 9 \
z & = - 9
\end{array} \right.$$ ?
A)? $( - 13 , - 27 , - 9 )$
B)? $( 13 , - 27 , - 9 )$
C)? $( - 13,27 , - 9 )$
D)? $( 13 , - 27,9 )$
E)? $( 13,27 , - 9 )$

Question

Use back-substitution to solve the system of linear equations.? $$\left\{ \begin{array} { c c } 
x - y + 2 z & = 22 \
3 y - 8 z & = - 9 \
z & = - 9
\end{array} \right.$$ ?
A)? $( - 13 , - 27 , - 9 )$
B)? $( 13 , - 27 , - 9 )$
C)? $( - 13,27 , - 9 )$
D)? $( 13 , - 27,9 )$
E)? $( 13,27 , - 9 )$

Quizplus · Accepted Answer

Given $z = -9$, substitute $z$ into the second equation to find $y$, and then use both $y$ and $z$ to find $x$ in the first equation. Solving the system gives $x = 13$, $y = -27$, and $z = -9$.

Use Back-Substitution to Solve the System of Linear Equations {x−y+2z=223y−8z=−9z=−9\left\{ \begin{array} { c c } x - y + 2 z & = 22 \\3 y - 8 z & = - 9 \\z & = - 9\end{array} \right.⎩⎨⎧​x−y+2z3y−8zz​=22=−9=−9​

Use Back-Substitution to Solve the System of Linear Equations $\left\{ \begin{array} { c c } x - y + 2 z & = 22 \\3 y - 8 z & = - 9 \\z & = - 9\end{array} \right.$