`documentclass{ctexart}
newcommand{ds}{displaystyle}
usepackage{amsmath}
usepackage{nicematrix}
usepackage{geometry}
geometry{
a4paper,
total={210mm,297mm},
left=30mm,
right=30mm,
top=25mm,
bottom=20mm
}
begin{document}
begin{equation}
A =left(begin{array}{c}
k_{11} gamma _{i_{1}}+k_{12} gamma _{i_{2}}+cdots+k_{1 r} gamma _{i_{r}} \
k_{21} gamma _{i_{1}}+k_{22} gamma _{i_{2}}+cdots+k_{2 r} gamma _{i_{r}} \
vdots \ vdots \
k_{s 1} gamma_{i_{1}}+k_{s 2} gamma_{i_{2}}+cdots+k_{s} gamma_{i_{r}}
end{array}right)=left(begin{array}{cccc}
k_{11} & k_{12} & cdots & k_{1 r} \
k_{21} & k_{22} & cdots & k_{2 r} \
vdots & vdots & & vdots \
k_{s 1} & k_{s 2} & cdots & k_{s}
end{array}right)
end{equation}
begin{equation}
A^{-1}=frac{1}{n}left(begin{array}{ccccc}
s-1 & s+1 & s & cdots & s \
s & s-1 & s+1 & cdots & s \
s & s & s-1 & cdots & s \
vdots & vdots & vdots & & vdots \
s & s & s & cdots & s+1 \
s+1 & s & s & cdots & s-1
end{array}right)
end{equation}
$begin{pmatrix}
1\
5\
5
end{pmatrix}$
$A \alpha _{i}= \beta _{i}, i=1,2,3 \Longleftrightarrow A\left( \alpha _{1}, \alpha _{2}, \alpha _{3}\right)=\left( \beta _{1}, \beta _{2}, \beta _{3}\right) \Longleftrightarrow \left( \alpha _{1}, \alpha _{2}, \alpha _{3}\right)^{\prime} A^{\prime}=\left( \beta _{1}, \beta _{2}, \beta _{3}\right)^{\prime}$
$$\left(\begin{array}{rrrrrr}1 & 0 & 0 & 2 & 1 & -3 \\ 1 & 2 & 0 & 1 & 0 & 4 \\ 1 & 2 & 3 & 3 & 2 & 1\end{array}\right) \longrightarrow\left(\begin{array}{rrrrrr}1 & 0 & 0 & 2 & 1 & -3 \\ 0 & 2 & 0 & -1 & -1 & 7 \\ 0 & 2 & 3 & 1 & 1 & 4\end{array}\right) \longrightarrow\left(\begin{array}{cccccc}1 & 0 & 0 & 2 & 1 & -3 \\ 0 & 1 & 0 & -\ds\frac{1}{2} & -\ds\frac{1}{2} & \ds\frac{7}{2} \\ 0 & 0 & 3 & 2 & 2 & -3\end{array}\right)$$
$$longrightarrowbegin{pNiceMatrix}[cell-space-limits=3pt]
1 & 0 & 0 & 2 & 1 & -3 \ 0 & 1 & 0 & -dsfrac{1}{2} & -dsfrac{1}{2} & dsfrac{7}{2} \ 0 & 0 & 1 & dsfrac{2}{3} & dsfrac{2}{3} & -1
end{pNiceMatrix}text{.,,So that,,,}A^{prime}=begin{pNiceMatrix}[cell-space-limits=3pt]
2 & 1 & -3 \ -dsfrac{1}{2} & -dsfrac{1}{2} & dsfrac{7}{2} \ dsfrac{2}{3} & dsfrac{2}{3} & -1
end{pNiceMatrix},quad A=begin{pNiceMatrix}[cell-space-limits=3pt]
2 & -dsfrac{1}{2} & dsfrac{2}{3} \ 1 & -dsfrac{1}{2} & dsfrac{2}{3} \ -3 & dsfrac{7}{2} & -1
end{pNiceMatrix}$$
$begin{pmatrix}
1\
5\
5\
2\
22\
2222\
end{pmatrix}$
$$ (A B)^{*}(i ; j)=(-1)^{i+j} A B\left(\begin{array}{l} 1, \cdots, j-1, j+1, \cdots, n \\ 1, \cdots, i-1, i+1, \cdots, n \end{array}\right) $$
$$ =(-1)^{i+j} \sum_{1 \leq v_{1}<v_{2}<\cdots<v_{n-1} \leq n} A\left(\begin{array}{l} 1, \cdots, j-1, j+1, \cdots, n \\ v_{1}, v_{2}, \cdots, v_{n-1} \end{array}\right) B\left(\begin{array}{l} v_{1}, v_{2}, \cdots, v_{n-1} \\ 1, \cdots, i-1, i+1, \cdots, n \end{array}\right) $$
$$ =(-1)^{i+j} \sum_{k=1}^{n} A\left(\begin{array}{l} 1, \cdots, j-1, j+1 \cdots, n \\ 1, \cdots, k-1, k+1 \cdots, n \end{array}\right) B\left(\begin{array}{l} 1, \cdots, k-1, k+1 \cdots, n \\ 1, \cdots, i-1, i+1 \cdots, n \end{array}\right) $$
$$ =\sum_{k=1}^{n}(-1)^{j+k} A\left(\begin{array}{l} 1, \cdots, j-1, j+1 \cdots, n \\ 1, \cdots, k-1, k+1 \cdots, n \end{array}\right)(-1)^{k+i} B\left(\begin{array}{c} 1, \cdots, k-1, k+1 \cdots, n \\ 1, \cdots, i-1, i+1 \cdots, n \end{array}\right) $$
$$ =\sum_{k=1}^{n} A_{j k} B_{k i}=\sum_{k=1}^{n} A^{*}(k ; j) B^{*}(i ; k)=B^{*} A^{*}(i ; j) . $$
end{document}`
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