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Log (3u) - log (u-2) = 0

the answer is 20/7 but i don’t know how to get it.

User LoVo
by
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1 Answer

5 votes

Explanation:

Let's use the log rules:

When we have the difference of 2 logs with the same base, it's like having a log with the same base as the base of our 2 logs, but the argument will be the quotient between the 2 arguments:

log(3u) + log(u-2) = 0

log[(3u)/(u-2)] = 0

By definition of log:

(3u)/(u-2) = 1

u ≠2

3u = u - 2

4 u = -2

u = -1/2

This should be the result.

I forgot the initial existance conditions:

u > 2.

Means that there is no solution to this equation.

User Evaldaz
by
4.4k points