用LDLT分解求解方程组c++

2. 用LDLT分解求解方程组: x1+2x2+3x3 = -3 2x1+x2-2x3 = 10 3x1-2x2+x3 = 7

用高斯消元法解方程组（C++）

1. 用高斯消元法解方程组： 21.0x1+67.0x2+88.0x3+73.0x4 =141.0 76.0x1+63.0x2 + 7.0x3+20.0x4 =109.0 85.0x2+56.0x3+54.0x4 =218.0 19.3x1+43.0x2+30.2x3+29.4x4 =93.7