Final answer:
To solve the system of equations using substitution, solve one of the equations for one variable and substitute it into the other equations. Finally, substitute the values of the variables back into one of the original equations.
Step-by-step explanation:
To solve the system of equations using substitution, we can solve one of the equations for one variable and substitute it into the other equations. Let's solve the first equation for x:
x = 2y + z - 11
Now, substitute this expression for x into the other two equations:
3(2y + z - 11) + 2y - z = 7
-2(2y + z - 11) + 2y + 4z = -9
Simplify and solve this system of equations to find the values of y and z. Finally, substitute the values of y and z back into the first equation to solve for x.