Use Back-Substitution to Solve the System of Linear Equations $$\left\{ \begin{array} { c l } 2 x - y + 5 z & = 24 \\y + 2 z & = 9 \\z & = 7\end{array} \right.$$

Multiple Choice

Use back-substitution to solve the system of linear equations. ?? $$\left\{ \begin{array} { c l } 2 x - y + 5 z & = 24 \\y + 2 z & = 9 \\z & = 7\end{array} \right.$$ ?

A) ? $$( - 8 , - 5,7 )$$
B) ?? $$( - 8,5,7 )$$
C) ?? $( - 8 , - 5 , - 7 )$
D) ?? $( - 7 , - 5,7 )$
E) ?? $( - 8 , - 5 , - 5 )$