问题 解答题

因式分①3(x-y)3+6y(y-x)2;②3x3-18x2+27x.

答案

①3(x-y)3+6y(y-x)2

=3(x-y)3+6y(x-y)2

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

=3(x-y)2(x+y);

②3x3-18x2+27x=3x(x2-6x+9)

=3x(x-3)2

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