(後只人季 解三元线性方程组 m1X1+a12X2+a1x3X3=b, 211+a22x2+a23x3=b2, a31x1+a32x2+a3x3=b3; 同样用消元法,可得: 1 2233 十 122331 132132 122133 132231,11 1=b1 2233 +a122b3+a13b2a32-b 2332 33 132213     + + = + + = + + = ; , , 3 1 1 3 2 2 3 3 3 3 2 1 1 2 2 2 2 3 3 2 1 1 1 1 2 2 1 3 3 1 a x a x a x b a x a x a x b a x a x a x b 解三元线性方程组 (1.4) 1 2 2 3 3 1 3 2 3 2 1 2 3 3 2 1 2 2 3 3 1 3 2 2 3 1 2 2 1 3 3 1 3 2 2 3 1, 1 1 2 2 3 3 1 1 2 2 3 3 1 2 2 3 3 1 1 3 2 1 3 2 1 1 2 3 3 2 ) ( a a b a b a b a a a b a a a b a a a a a a x b a a a a a a a a a a a a a a + + − − − − − = + + − 同样用消元法，可得：