设3^x=4^y=36,则 2/x+1/y=/>

设3^x=4^y=36,则 2/x+1/y=/>
设3^x=4^y=36,则 2/x+1/y=

/>

设3^x=4^y=36,则 2/x+1/y=/>

取对数
xlg3=ylg4=lg36
1/x=lg3/lg36
1/y=lg4/lg36
所以原式=2lg3/lg36+lg4/lg36
=(lg3²+lg4)/lg36
=lg(3²×4)/lg36
=lg36/lg36
=1

取对数
令log 3 36=x
log 4 36=y
所以
2/x+1/y=2/log3 36 +1/log4 36
=2*log 36 3+log36 4
=log 36 9+log36 4
=log36 36
=1