aX +aix, +...+ainx, = 0asixi +as2X, +... +asnxn = 03buixi + bi2x, + ...+ binx, = 0buxi + b2x, + ...+bmxn = 0的解空间.证：设方程组①②③分别为X=0AX = 0,BX = 0,B86.6子空间的交与和Λ§6.6 子空间的交与和 ③ 的解空间. 证：设方程组①,②,③分别为 11 1 12 2 1 1 1 2 2 11 1 12 2 1 1 1 2 2 0 0 0 0 n n s s sn n n n t t tn n a x a x a x a x a x a x b x b x b x b x b x b x  + + + =   + + + =  + + + =   + + + =  ( ) 0, 0, 0 A AX BX X B = = =