首页 > 留学知识库

问题: 哥哥姐姐帮帮忙拉

n^2(m-2)-n(2-m)

(a^2+1)^2-4a^2

根号8--根号2(根号2+2)
(-3)^2+根号8-|1-2*根号2|
(注:^平方,例:2^5表示二的五次方;*表示×)

解答:

n^2(m-2)-n(2-m) =
n^2(m-2)+n(m-2) =
n(m-2)(n+1)

(a^2+1)^2-4a^2 =
[(a^2+1)-2a ](a^2+1)+2a]=
(a-1)^2*(a+1)^2=
[(a-1)(a+1)]^2=


√8-√2(√2+2)=
2√2-√2(√2+2)=
√2[2-(√2+2)]=
√2*(-√2)=
-2


(-3)^2+√8-|1-2√2|=
9+2√2-(2√2-1)=
9+2√2-2√2+1=
10