Select the correct answer.
Which system of equations can be represented by this matrix?

C

Step-by-step explanation: As you most likely know, the matrix represents the system of equations. If you assume that x is the far left column, that y is the column adjacent to it, and that y is to the left of the line, you can assume that these are the equations represented:

1x-3y+2z=-9

1x+0y+1z=1

0x+2y-1z=7

which can be simplified to

x-3y+2x=-9

x+z=1

2y-z=7