问题 填空题

计算:(x-1)2-2(x-1)=______.

答案

法一:(x-1)2-2(x-1)

=x2-2x+1-(2x-2)

=x2-2x+1-2x+2

=x2-4x+3;

法二:(x-1)2-2(x-1)

=(x-1)[(x-1)-2]

=(x-1)(x-3)

=x2-3x-x+3

=x2-4x+3.

故答案为:x2-4x+3.

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