(log43+log83)(log32+log92)-log1/2乘以32的根号的4次方

用换底公式，原式
=(ln3/ln4+ln3/ln8)(ln2/ln3+ln2/ln9)-ln(32的根号的4次方)/ln(1/2)
=[ln3/(2*ln2)+ln3/(3*ln2)]*[ln2/ln3+ln2/(2*ln3)]-1/4[ln(2^5)]/(-ln2)
=(1/2+1/3)*ln3/ln2*(1+1/2)*ln2/ln3-5/4*ln2/(-ln2)
=5/6*3/2+5/4
=5/2

说清楚点…………哪个是底数？？