列主元高斯消元法解线性方程组，其中的系数矩阵和右端向量大家可根据自己的需求更改，程序中已代入相应的具体矩阵-Out PCA Gaussian elimination method for solving linear equations, the coefficient matrix and the right end of the vector can be changed according to their needs, the program has been substituted into the specific matrix