因式分解,①4(3a+2b)²-9(3a-2b)²②5y(x-2y)-20y(2x-y)²
问题描述:
因式分解,①4(3a+2b)²-9(3a-2b)²②5y(x-2y)-20y(2x-y)²
答
①4(3a+2b)²-9(3a-2b)²
=[2(3a+2b)+3(3a-2b)][2(3a+2b)-3(3a-2b)]
=(15a-2b)(-3a+10b)
=-(15a-2b)(3a-10b)
②5y(x-2y)-20y(2x-y)²
=5y(x-2y)[1-4(x-2y)]
=5y(x-2y)(1-4x+8y)