Question

怎么把它化成行阶梯形矩阵,

Answer 1

A -->

r2-2r1,r3-3r1,r4-4r1

1 5 3 4 9

0 -4 1 -1 -10

0 -8 -7 -7 -24

0 -12 -11 -10 -35

r3-2r2,r4-3r2

1 5 3 4 9

0 -4 1 -1 -10

0 0 -9 -5 -4

0 0 -14 -7 -5

r4-(14/9)r3

1 5 3 4 9

0 -4 1 -1 -10

0 0 -9 -5 -4

0 0 0 7/9 11/9