(log2 3/log2 4+log2 3/log2 8)(log3 5/log3 3+log3 5/log3 9)(log5 2/log5 5+log5 2/log5 25)=[(5log2 3)/6][(3log3 5)/2][(3log5 2)/2]然后全部换成以2为底的对数得上式=(5/6)(3/2)(3/2)[(log2 3/log2 2)(log2 5/log2 3)(log2 2/log2 5)]=15/8