原式=（ x+3 x?2 - 1 x?2 ）× 3 (x+2)(x?2) = x+2 x?2 × 3 (x+2)(x?2) = 3 (x?2)2 = 3 x2?4x+4 ． ∵x2-4x+1=0，∴x2-4x=-1，∴原式= 3 ?1+4 =1．
