问题 解答题

(1)因式分3x2-6xy+3y2

(2)化简:(x+2)2-(x+1)(x-1).

答案

(1)3x2-6xy+3y2

=3(x2-2xy+y2),

=3(x-y)2

(2)(x+2)2-(x+1)(x-1),

=x2+4x+4-x2+1,

=4x+5.

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