【问题描述】已知线性方程组AX=B，求解该方程组。参考算法：

消去法：将列向量B加到矩阵A的最后一列，构成增广矩阵AB。对AB进行下列三种初等变换，使原矩阵A的部分的主对角线上的元素均为1，其余元素均为0，则原列向量B的部分即为X的值：

1. 将矩阵的一行乘以一个不为0的数

2. 将矩阵的一行加上另一行的倍数

3. 交换矩阵中两行的位置

- [ Question descr iption ] known system of linear equations AX=B,
solves this system of equations. Reference algorithm: 娑堝幓娉? Will
arrange in order vector B to add to matrix A last the row,
constitution augmentation matrix AB. Carries on the following three
kind of elemetary operations to AB, causes original matrix A in the
part principal diagonal element is 1, other elements are 0, then the
original row vector B part is X value: 1. a matrix line while take as
0 several 2. adds on a matrix line in another line of multiples 3.
exchanges matrices two lines of positions