设3^x=4^y=36那2/x+1/y的值为多少?

设3^x=4^y=36那2/x+1/y的值为多少?
设3^x=4^y=36那2/x+1/y的值为多少?

设3^x=4^y=36那2/x+1/y的值为多少?
3^x=4^y=36
x=以3为低的log36=lg36/lg3,y=以4为低的log36=lg36/lg4
2/x+1/y=2/lg36/lg3+1/lg36/lg4
=(2lg3+lg4)/lg36
=(lg9+lg4)/lg36
=lg36/lg36
=1

x=log(3)36,y=log(4)36
2\x+1\y=log(36)9 +log(36)4
=log(36)36
=1

3^X乘4^Y=36X36=3^4乘4^2,所以x=4.Y=2代入可得1 。这样做适合七年级学生