=㏒3/㏒2+㏒4/㏒3+㏒5/㏒4+㏒6/㏒5+㏒7/㏒6+㏒8/㏒7+㏒9/㏒8
你的题目应该是写错了,但有一个知识可供你参考
loga(b)*logb(c)=loga(c); loga(b)*logb(c)*logc(d)=loga(d).
log2(3)*log3(4)*log4(5)*log5(6)*log6(7)*log7(8)=log2(8)=3
log(2,3)+log(3,4)+log(4,5)+log(6,7)+log(7,8)+log(8,9)
=log(2,3)+2log(3,2)+(1/2)log(2,5)+log(6,7)+3log(7,2)+(2/3)log(2,3)
=(5/3)log(2,3)+(1/2)log(2,5)+2log(3,2)+log(6,7)+3log(7,2)