分解因式:(1-7t-7t2-3t3)(1-2t-2t2-t3)-(t+1)6=______.

1个回答

  • 解题思路:可设(t+1)3=x,y=t2+t+2,将(1-7t-7t2-3t3)(1-2t-2t2-t3)-(t+1)6变形为(2y-3x)(y-x)-x2的形式分解因式.

    设(t+1)3=x,y=t2+t+2,则

    原式=[2(t2+t+2)-3(1+3t+3t2+t3)][(t2+t+2)-(1+3t+3t2+t3)]-[(t+1)3]2

    =(2y-3x)(y-x)-x2

    =2x2-5xy+2y2

    =(2x-y)(x-2y)

    =[2(t3+3t2+3t+1)-(t2+t+2)][(t3+3t2+3t+1)-2(t2+t+2)]

    =(2t3+5t2+5t)(t3+t2+t-3)

    =t(2t2+5t+5)(t-1)(t2+2t+3).

    故答案为:t(2t2+5t+5)(t-1)(t2+2t+3).

    点评:

    本题考点: 因式分解-十字相乘法等.

    考点点评: 本题考查了用换元法分解因式,它能够把一些整式化繁为简,化难为易,对此应注意总结能用换元法分解因式的特点,寻找解题技巧.