3^a=2
a=log3(2)
log3(8)-2log3(6)
=3log3(2)-2[log3(3)+log3(2)]
=3a-2(1+a)
=a-2为什么是a=log3(2)3^a=2,等式两边同取以3为底的对数可得a=log3(2)