若常数项 b,=b,=..=b,=0，即aixi+aix+...+ainxn=0a2iXj + a22X2 + ... + a2nx, = 0(2)[aniX, +an2X, +...+annn=0则称（2）为齐次线性方程组2简记为ajx, =0, i=1,2,..,n.j=1R区F$2.7Cramer法则§2.7 Cramer法则 1 0, 1,2, , . n ij j j a x i n =  = = 则称（2）为齐次线性方程组． 11 1 12 2 1 21 1 22 2 2 1 1 2 2 0 0 0 n n n n n n nn n a x a x a x a x a x a x a x a x a x  + + + =  + + + =   + + + =  (2) 若常数项 b b b 1 2 = = = = n 0, 即 简记为