(1)16(6x-1)(2x-1)(3x+1)(x-1)+25, =[(6x-1)(4x-2)][(6x+2)(4x-4)]+25, =(24x 2 -16x+2)(24x 2 -16x-8)+25, =(24x 2 -16x) 2 -6(24x 2 -16x)-16+25, =(24x 2 -16x) 2 -6(24x 2 -16x)+9, =(24x 2 -16x-3) 2 ; (2)(6x-1)(2x-1)(3x-1)(x-1)+x 2 , =[(6x-1)(x-1)][(2x-1)(3x-1)]+x 2 , =(6x 2 -7x+1)(6x 2 -5x+1)+x 2 , =(6x 2 -6x+1-x)(6x 2 -6x+1+x)+x 2 , =(6x 2 -6x+1) 2 -x 2 +x 2 , =(6x 2 -6x+1) 2 ; (3)(6x-1)(4x-1)(3x-1)(x-1)+9x 4 , =[(6x-1)(x-1)][(4x-1)(3x-1)]+9x 4 , =(6x 2 -7x+1)(12x 2 -7x+1)+9x 4 , 令t=6x 2 -7x+1,则12x 2 -7x+1=t+6x 2 , ∴原式=t(t+6x 2 )+9x 4 , =t 2 +6?t?x 2 +9x 4 , =(t+3x 2 ) 2 , =(6x 2 -7x+1+3x 2 ) 2 , =(9x 2 -7x+1) 2 . |