log8 9 =a ,log 9 25 =b,求lg22/3log2(3)=a,log3(5)=b,log2(3)=3a/2,log2(5)/log2(3)=b,log2(5)=b*log2(3)=3ab/2.lg2=log2(2)/log2(10)=1/[log2(2)+log2(5)]=1/[1+3ab/2]=2/(2+3ab).