log3 18-4分之一log3 16
=log3(18)-1/4*log3(16)
=log3(18)-log3(16)^1/4
=log3(18)-log3(2)
=log3(18/2)
=log3(9)
=2log3(18)-log3(2)这里怎么变成log3(2)了，不应该是log3(4）吗，为什么16^1/4=2(2^4=16)