In(x-5)+In(x+3)-2In2=In(2x-9)
问题描述:
In(x-5)+In(x+3)-2In2=In(2x-9)
答
In(x-5)+In(x+3)-2In2=In(2x-9)
ln[(x-5)(x+3)/4]=ln(2x-9)
(x-5)(x+3)/4=2x-9
x*x-10x+21=0
所以x=3或7
又x-5>0
所以x=7
答
In(x-5)+In(x+3)-2In2=In(2x-9)
ln[(x-5)(x+3)/4]=ln(2x-9)
(x-5)(x+3)/4=2x-9
x*x-10x+21=0
x=3 或者 x=7
x=3 时 In(x-5) 失去意义
所以 x=7
答
In(x-5)+In(x+3)-2In2=In((x-5)*(x-3)/4)=In(2x-9)
(x-5)*(x+3)/4=2x-9
所以
x=3或7