【初一下】【回答后给分】已知x²-2x=2,将代数式(x-1)²+(x+3)(x-3)+(x-3)(x-1)化简并求值.

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/02 13:50:35
【初一下】【回答后给分】已知x²-2x=2,将代数式(x-1)²+(x+3)(x-3)+(x-3)(x-1)化简并求值.

【初一下】【回答后给分】已知x²-2x=2,将代数式(x-1)²+(x+3)(x-3)+(x-3)(x-1)化简并求值.
【初一下】【回答后给分】已知x²-2x=2,将代数式(x-1)²+(x+3)(x-3)+(x-3)(x-1)化简并求值.

【初一下】【回答后给分】已知x²-2x=2,将代数式(x-1)²+(x+3)(x-3)+(x-3)(x-1)化简并求值.
(x-1)²+(x+3)(x-3)+(x-3)(x-1)
=(x-1)²+(x-3)[(x+3)+(x-1)]
=(x-1)²+(x-3)[2x+2]
=x²-2x+1+2x²+2x-6x-6
=2+1+2x²-4x-6
=3+2(x²-2)-6
=3+4-6
=1

原式化简=3x²-6x-5=3(x²-2x)-5,带入x²-2x=2,
得=1