线性方程组 线性方程组1x1+x2 -2x4=-64x1-x2-x3-x4=13x1-x2-x3 =3方程组2X1+MX

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  • 两个方程组同解的充分必要条件是行向量组等价

    设方程组1,2的增广矩阵分别为A1,A2

    考虑分块矩阵 H = (A1; A2) --上下放置

    则 r(A1)=r(H)=r(A2)

    H =

    1 1 0 -2 -6

    4 -1 -1 -1 1

    3 -1 -1 0 3

    1 m -1 -1 -5

    0 n -1 -2 -11

    0 0 1 -2 -t+1

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

    1 1 0 -2 -6

    0 -5 -1 7 25

    0 -4 -1 6 21

    0 m-1 -1 1 1

    0 n -1 -2 -11

    0 0 1 -2 -t+1

    r2-r3

    1 1 0 -2 -6

    0 -1 0 1 4

    0 -4 -1 6 21

    0 m-1 -1 1 1

    0 n -1 -2 -11

    0 0 1 -2 -t+1

    r3-4r2,r4+(m-1)2,r5+nr2

    1 1 0 -2 -6

    0 -1 0 1 4

    0 0 -1 2 5

    0 0 -1 m 4m-3

    0 0 -1 n-2 4n-11

    0 0 1 -2 -t+1

    r4-r3,r5-r3,r6+r3

    1 1 0 -2 -6

    0 -1 0 1 4

    0 0 -1 2 5

    0 0 0 m-2 4m-8

    0 0 0 n-4 4n-16

    0 0 0 0 -t+6

    由 r(A1)=r(H) 知 m=2,n=4,t=6.

    易知,此时 r(A2) = 3 = r(A1) = r(H).

    请问这是哪本教材中的题目,望告知!