Which operation should you perform next to lead to a solution of the system in as few steps as possible?

Question

augmented matrix

1 3 -1 10

2 8 0 22

-2 2 1 -3

a. replace row 2 with some of rows 1 and 2

b replace row 2 with some of rows 2 and 3

c replace row 3 with some of rows 1 and 3

I think the answer is c, im still not sure

Answer 1

It's (c)

If you do this, you get

1 3 -1 10

2 8  0 22

1 5  0  7

This is good because you have eliminated the z variable from both the second and third rows, so you can solve the last two equations more easily.  If you do (a) or (b), you can't get two zeros in the same column so solving is harder.