记 a ⊙ 6 A C, 因为 a1+02+0g3=B a1+o2+2@3=β3 a%+2c2+3C3=f 即 4 c? 3 记 1 1 2 2 3 3 B A ,               = =             1 2 3 1 1 2 3 2 1 2 3 3 2 2 3              + + =  + + =  + + = 因为即 1 1 2 2 3 3 1 1 1 1 1 2 1 2 3                 =                令 1 1 1 1 1 2 1 2 3 C     =      