若x满足2x+2^x=5,y满足2y+2log2(y-1)=5,则x+y=?
问题描述：
若x满足2x+2^x=5,y满足2y+2log2(y-1)=5,则x+y=?
请给出详解,
答
设t=log2(y-1),则y=2^t+1代入到2y+2log2(y-1)=5中,可整理得到2^(t+1)+2(t+1)=5与2x+2^x=5比较,可得t+1=x,即log2(y-1)=x-1y-1=2^(x-1),于是2y-2=2^x由2x+2^x=5,得到2^x=5-2x,代入上式得2y-2=5-2x,可算出x+y=7/2...