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2^x+8 = 3
Solve the exponential equation. Express the solution set in terms of natural logarithms.
How do I do this? Please show work.

2006-12-10 11:15:23 · 4 answers · asked by Anonymous in Science & Mathematics Mathematics

4 answers

2^x+8=3 There is no real solution solution.
2^x=-5
2 ln x=ln -5
ln x=.5 ln -5
x=√-5

2006-12-10 11:20:29 · answer #1 · answered by yupchagee 7 · 15 0

Would it help to know that ln( 2^x) = x * ln( 2) ?

So you can use natural logarithms (ln) to solve your equation by taking the logarithm of both sides and bringing out the x per the definition above.

first

2^x + 8 = 3 becomes

2^x = -5 well now that won't work as ln is only defined for positive numbers. Now I am not sure what you should do.

2006-12-10 11:19:48 · answer #2 · answered by rscanner 6 · 0 0

first of all let me correct your problem
2^(x+8)=3
as no degree(or power) of a positive number can result in negative number

now take the natural (to the base 'e' ) log of equation [note=u can solve this by taking the log to any base, provided u know the logarithmic table for that base]---

ln[2^(x+8)]=ln3
(x+8)ln2=ln3 ln a^b = b ln a
x+8 = ln3/ln2
x= (ln3/ln2) - 8

the answer is
x = - 6.415

2006-12-10 11:30:31 · answer #3 · answered by Sadanand Lamkhede 1 · 0 0

precise, to initiate, you're taking ln of both area (organic and organic log) so that you get ln4^(x+7)=ln6 utilizing the regulation of logarithms, you need to simplify the equation to: (x+7)ln4=ln6 simplify some extra... (divide by utilizing ln4 on both area) (x+7)=ln6/ln4 so, x= ln6/ln4 -7 :D

2016-11-25 19:31:39 · answer #4 · answered by Anonymous · 0 0

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