若3^a=2,则log3(8)-2log3(6)用a的代数式可表现为

问题描述:

若3^a=2,则log3(8)-2log3(6)用a的代数式可表现为

∵3^a=2
∴log3 2=a
log3(8)-2log3(6)
=3log3 2-2(log3 3+log3 2)
=3log3 2-2-2log3 2
=log3 2 -2
=a-2