刘老师 线性代数求解 17和18 麻烦写出解答步骤

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17.AE=0 1 -21 0 -1-2 -1 01 0 00 1 00 0 1r1+r2,c1+c2
2 1 -31 0 -1-3 -1 01 0 01 1 00 0 1r3+3r2,c3+3c2
2 1 01 0 -10 -1 -61 0 01 1 30 0 1r2-(1/2)r1
2 0 00 -1/2 -1
0 -1 -61 -1/2 0
1 1/2 30 0 1r3-2r2
2 0 00 -1/2 0
0 0 -41 -1/2 1
1 1/2 20 0 1令C=1 -1/2 1
1 1/2 20 0 1则 C'AC = diag(2,-1/2,-4).
18. 这个简单, 一次变换即可
C=0 1 01 0 00 0 1