SOLUTION: Please help! Final is on Monday. Here is the problem I am stuck on: (2/5)^x = 7^1-x I came up with ln7/ln(2/5)+ln7 = 1.890 but my roomate keeps coming up with something

Question 80792: Please help! Final is on Monday.
Here is the problem I am stuck on:
(2/5)^x = 7^1-x
I came up with ln7/ln(2/5)+ln7 = 1.890 but my roomate keeps coming up with something different. Am I right? Thank you so much.
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

Take the log base 10 of both sides(in this case, it doesn't matter which base we use)

Use the identity

Distribute log(7) to (1-x)

Get all x terms to one side

Factor out an x

Divide both sides by to isolate x

So you are correct the answer is

or

Check:
Plug in to check

works
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