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.
计算:(x-1)2-2(x-1)=______.
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.