因式分解:(x+2y)(3x2-4y2)-(x+2y)2(x-2y)=________.

题目

因式分解:(x+2y)(3x2-4y2)-(x+2y)2(x-2y)=________.
1.21a3b-35a2b3=_________．
2.3x2yz+15xz2-9xy2z=__________．
3.x2-2xy-35y2=(x-7y)( )．
4.2x2-7x-15=(x-5)( )．
5.20x2-43xy+14y2=(4x-7y)( )．
6.18x2-19x+5=( )(2x-1）
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答案

1.21a3b-35a2b3=7a^2b(3ab-5b^2)
2.3x2yz+15xz2-9xy2z=3xz(xy+5z-3y^2)
3.x2-2xy-35y2=(x-7y)(x+5y )．
4.2x2-7x-15=(x-5)( 2x+3 )．
5.20x2-34xy+14y2=(4x-7y)( 5x-2y )．
6.18x2-19x+5=(9x-5 )(2x-1）