题目阅读下面材料,并解决问题:
2+11=(2+1)(2−1)2−1=2−1;
3+21=(3+2)(3−2)3−2=3−2;
2+31=(2+3)(2−3)2−3=2−3;
……(1)填空:
11+101=______;
(2)猜想:当
n是正整数时,
n+1+n1=______;(用含
n的式子表示)
(3)计算:
2+11+3+21+2+31+…+2023+20221=______. 知识点:实数的运算章节:未标注
答案与解析
答案
(1)
11+101=(11+10)(11−10)11−10=11−10,
故答案为:
11−10;
(2)n+1+n1=(n+1+n)(n+1−n)n+1−n=n+1−n,
故答案为:
n+1−n;
(3)2+11+3+21+2+31+…+2023+20221=2−1+3−2+2−3+…+2023−2022=−1+2023=2023−1,
故答案为:
2023−1.
解析
(1)
11+101=(11+10)(11−10)11−10=11−10,
故答案为:
11−10;
(2)n+1+n1=(n+1+n)(n+1−n)n+1−n=n+1−n,
故答案为:
n+1−n;
(3)2+11+3+21+2+31+…+2023+20221=2−1+3−2+2−3+…+2023−2022=−1+2023=2023−1,
故答案为:
2023−1.