log以15为底2＋log以15为底3/2＋log - 知识问答

log以15为底2＋log以15为底3/2＋log以15为底20－log以15为底4 求值

1个回答

（1）log以15为底2＋log以15为底3/2＋log以15为底20－log以15为底4
= log以15为底[(2)*(3/2)*20/4]
= log以15为底15
= 1.
（2）(log以6为底2)^2＋(log以6为底2)×(log以6为底3)＋log以6为底18
= (log以6为底2)(log以6为底2+log以6为底3)＋log以6为底18
= log以6为底2＋log以6为底18
= log以6为底(6^2)
= 2.

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