9＾-x-2*3＾1-x=27
3^-2x-3(3*3^-x)=27
设3^-x=t因3^-x>0故t>0
t²-6t=27
(t-3)²=36
解得：t=9①t=-3（因t>0故t=-3舍去）
将3^-x 代入①得：
3^-x=9
x=-2
解方程 9＾-x-2*3＾1-x=27
解方程 9＾-x-2*3＾1-x=27
9的负x次方-2*3的1-x次方=27
9的负x次方-2*3的1-x次方=27
数学人气：919 ℃时间：2020-01-30 10:47:06
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