Answer
Blanks left to right, by row:
$1,1,-1,1$ (row 1)
$1,0,2,-3$ (row 2)
$0,2,-1,3$ (row 3)
Work Step by Step
The numbers are determined by the coefficients of the variables, and any non-existent variables are replaced by 0.
Row 1: x is 1, y is 1, z is -1, solution (# after equal sign) is 1.
Row 2: x is 1, y is 0 (not there), z is 2, solution (# after equal sign) is -3.
Row 3: x is 0 (not there), y is 2, z is -1, solution (# after equal sign) is 3.
