please help me, can't find the answer anywhere. f^-1(3) if f(x)=3x+ln x
I need to find a fractional solution. I think it's 4/5 or something like that, but I'm not sure. If anyone here is adept at Pre-Calculus please respond.

Question

please help me, can't find the answer anywhere. f^-1(3) if f(x)=3x+ln x
I need to find a fractional solution. I think it's 4/5 or something like that, but I'm not sure. If anyone here is adept at Pre-Calculus please respond.

ganeshie8 · Answer

You want to solve $x$ in :

$3 = 3x+\ln x$

anonymous · Answer

your job is to solve $$3x+\ln(x)=3$$

anonymous · Answer

don't try algebra
do it "by inspection"

anonymous · Answer

am I supposed to try different numbers in the place of x until I find it?

anonymous · Answer

i.e guess at a solution
make an educated guess
you cannot solve this using algebra because you have both $3x$ and $\ln(x)$ 
make a guess   
i bet you get it on the first or second try

anonymous · Answer

hint, start with the smallest positive integer

ganeshie8 · Answer

there is a very natural number to try
usually your teacher makes it easy for you to guess, give it a try..

anonymous · Answer

this is what I have so far. 3=x+e^3

jim_thompson5910 · Answer

as @satellite73 said, you'll probably get it on your $\large \text{first}$ try

anonymous · Answer

1 works, but he said that's not the answer he's looking for.

anonymous · Answer

no  you are trying to manipulate it (incorrectly) 
at the risk of repeating myself 
don't be shy, give it a try

anonymous · Answer

really?

jim_thompson5910 · Answer

x = 1 is the only solution

anonymous · Answer

yeah, he wants us to solve it and apparently you can find a fractional answer

anonymous · Answer

cause there aint another one

anonymous · Answer

he handed out a multiple choice quiz last week with this question and I guessed it, but it's coming up on the test soon and I want to figure it out before. all of the options were fractions.

ganeshie8 · Answer

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