将矩阵初等行变换为行阶梯形矩阵.

1.
r2-2r1,r3-5r1
1 1 0 0 5
0 -1 1 2 -9
0 -2 2 2 -22
r3-2r2
1 1 0 0 5
0 -1 1 2 -9
0 0 0 -2 -4
2.
r2-r1-2r3,r3-2r1
1 -5 2 -3 3
0 0 0 0 8
0 14 -2 7 -12