【正确答案】正确答案：X(E—C ^-1 B) ^T C ^T =X[C(E—C ^-1 B)] ^T =X(C一B) ^T =E 即X=X(C一B) ^T [(C—B) ^T ] ^-1 =E[(C一B) ^T ] ^-1 =[(C—B) ^T ] ^-1