已知向量组(alpha_{1},alpha_{2},alpha_{3},分别可由向量组beta_{1},beta_{2},beta_{3},线性表示，即begin{equation}left{begin{aligned}alpha_{1}&=beta_{1}-beta_{2}+beta_{3}alpha_{2}&=beta_{1}+beta_{2}-beta_{3}alpha_{3}&=-beta_{1}+beta_{2}+beta_{3}end{aligned}right.end{equation}，)(1)试写出这一线性表示的系数矩阵(K=(quad)。)
A
A.(K=begin{pmatrix} 1 & 1 & -1 -1 & 1 & 1 1 & -1 & 1 end{pmatrix})
B
B.(K=begin{pmatrix} 1 & -1 & 1 -1 & 1 & 1 1 & -1 & 1 end{pmatrix})
C
C.(K=begin{pmatrix} -1 & 1 & 1 1 & -1 & 1 1 & 1 & -1 end{pmatrix})
D
D.(K=begin{pmatrix} 1 & 1 & -1 1 & -1 & 1 1 & 1 & -1 end{pmatrix})
