化简,求值:(a-2b+1)(a+2b-1)+(2b-1)²,其中a=598,b=998
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/20 15:36:40
![化简,求值:(a-2b+1)(a+2b-1)+(2b-1)²,其中a=598,b=998](/uploads/image/z/573450-42-0.jpg?t=%E5%8C%96%E7%AE%80%2C%E6%B1%82%E5%80%BC%3A%28a-2b%2B1%29%28a%2B2b-1%29%2B%282b-1%29%26%23178%3B%2C%E5%85%B6%E4%B8%ADa%3D598%2Cb%3D998)
化简,求值:(a-2b+1)(a+2b-1)+(2b-1)²,其中a=598,b=998
化简,求值:(a-2b+1)(a+2b-1)+(2b-1)²,其中a=598,b=998
化简,求值:(a-2b+1)(a+2b-1)+(2b-1)²,其中a=598,b=998
解:(a-2b+1)(a+2b-1)+(2b-1)²
=[a-(2b-1)][a+(2b-1)]+(2b-1)²
=a²-(2b-1)²+(2b-1)²
=a²
=598²
=(600-2)²
=360000-2400+4
=357604
(a-2b+1)(a+2b-1)+(2b-1)²
=-(a+2b-1)(a+2b-1)+(2b-1)²
=-(a+2b-1)²+(2b-1)²
=-(598+998*2-1)²+(998*2-1)²
=-(600-2+(1000-2)*2-1)²+((1000-2)*2-1)²
=-(600+2000-2-4-1)²+(2000-4-1)²
……
不用我继续解下去了吧
好吧我慢了
整理原式得:[a-(2b-1)][a+(2b-1)]+(2b-1)²
有平方差公式得:a²-(2b-1)²+(2b-1)²
所以原式=a²=598²=(600-2)²=360000+4-2400=357604