If you solve the following system of equations by substitution, which statement is true?

x = z
x - 2y + z = 6
2x + y - 2z = 1
A. You can substitute z for x into the second and third equations.
B. You can substitute x for z into the second and third equations.
C. Both methods will work
D. Neither methods will work

My answer is C since the first equation stated that x=z. I just wanted to make sure it was right.

You are correct! The answer is C. Both methods will work.

To verify this, let's explain how to solve the system of equations by substitution.

Given the first equation, x = z, we can substitute x for z in the second and third equations.

Using substitution, we replace z with x in the second equation:

x - 2y + z = 6
x - 2y + x = 6
2x - 2y = 6

Similarly, we substitute x for z in the third equation:

2x + y - 2z = 1
2x + y - 2x = 1
y = 1

Now we have a system of two equations:
2x - 2y = 6
y = 1

To solve this system, we can substitute y = 1 into the first equation:

2x - 2(1) = 6
2x - 2 = 6
2x = 8
x = 4

Finally, substituting x = 4 and y = 1 into the first equation:

x = z
4 = z

So the solution to the system of equations is x = 4, y = 1, and z = 4.

Therefore, both substituting z for x and x for z will work in solving this system of equations.