1-a/4过程？如果没猜错，你的题目不完整对的呀6^a = 8两边取以6为底的对数:a = log(6)8 = log(6)4^3 = 3log(6)2 = 3log(6)(6/4)= 4[log(6)6 - log(6)4]= 4[1 - log(6)4)log(6)4 = 1 -a/4