9的3n+1次方=27的n-1次方
3^2(3n+1)=3^3(n-1)
2(3n+1)=3(n-1)
6n+2=3n-3
3n=-5
n=-5/3
( 2/1+a - a-2/a+1)÷a^2-4+a/2a
=a/a+1 *1/a^2-4+a/2a
=1/a(a+1)-4+a/2a
=(1-(4+a)(a+1))/2a(a+1)
=(1-4a-4-a^2-a)/2a(a+1)
=-(a^2+5a+3)/2a(a+1)
9^(3n+1)=27^(n-1)
(3^2)^(3n+1)=(3^3)^(n-1)
3^2(3n+1)=3^3(n-1)
2(3n+1)=3(n-1)
6n+2=3n-3
6n-3n=-2-3
3n=-5
n=-5/3
2/1+a - a-2/a+1)÷a^2-4+a/2a用文字描述一下
9的3n+1次方=3的6n+2次方
27的n-1次方=3的3n-3次方
所以6n+2=3n-3
n=-5/3
后面一题题目怪怪的,应该有漏什么吧,个人意见,仅供参考