因式分解:(3x+2y-3)(3x+2y+7)-11

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因式分解:(3x+2y-3)(3x+2y+7)-11因式分解:(3x+2y-3)(3x+2y+7)-11因式分解:(3x+2y-3)(3x+2y+7)-11分析:把()3x+2y)看成是一个整体,再用

因式分解:(3x+2y-3)(3x+2y+7)-11
因式分解:(3x+2y-3)(3x+2y+7)-11

因式分解:(3x+2y-3)(3x+2y+7)-11
分析:把()3x+2y)看成是一个整体,再用"十"字相乘法,
(3x+2y-3)(3x+2y+7)-11
=(3x+2y)²+4(3x+2y)-21-11
=(3x+2y)²+4(3x+2y)-32
=[(3x+2y)+8][(3x+2y)-4]
=(3x+2y+8)(3x+2y-4)

﹙3x+2y-3﹚﹙3x-2y+7﹚-11
=﹙3x+2y-3﹚﹙3x+2y-3+10﹚-11
=﹙3x+2y-3﹚²+10﹙3x+2y-3﹚-11
=﹙3x+2y-3-1﹚﹙3x+2y-3+11﹚
=﹙3x+2y-4﹚﹙3x+2y+8﹚.

令a=2x+3y
原式=(a-3)(a+7)-11
=a²+4a-21-11
=a²+4a-32
=(a+8)(a-4)
=(2x+3y+8)(2x+3y-4)