(1)(4x-y+1)2 解:原式=(4x-y)2+2(4x-y)+1 =16x2-8xy+y2+8x-2y+1 (2)(3x-2y+)2 解:原式=(3x-2y)2+2×(3x-2y)×+ =9x2-12xy+4y2+2x-y+ (3)(a-b+2c)2