## irvine 3 years ago What is the solution of log 2x – 3^125 = 3 ? Please help im taking a test right now

1. Hero

Hi

2. irvine

hi

3. jimmyrep

is LHS = log of (2x - 3^125) or just log of 2x?

4. irvine

hmm. i have no clue the question is exactly the way i posted it that's what confused me

5. Hero

6. irvine

That is basically why i dont understand it

7. gabrielbean

iw ould say move the log2x to one side on its own then re-arrange to remove the log then solve for x log2x=3+3^125 (assuming log is to base ten) 10^(3+3^125)=2x x=(10^(3+3^125))/2 i think...

8. jimmyrep

yes - thats right

9. irvine

thank you so much! :)

10. Hero

For some reason, I keep getting false for the answer

11. gabrielbean

so do i but that may be to do with the calculators memory

12. irvine

maybe

13. Hero

wolfram alpha's solution: http://www.wolframalpha.com/input/?i=log%282x%29%3D3%2B3^125%2C+x&a=*FunClash.log-_*Log10.Log-

14. irvine

i went to this website too and i got a completely different answer i guess it might be the way i typed the equation in

15. Hero

How did you type it in, and what website was that?

16. Hero

Ah, I think it's log base 2 of x

17. irvine

log 2x – 3^125 = 3 and the website was wolframalpha too

18. irvine

but the choices in the test are way different though

19. Hero

Hold on a sec

20. Hero

21. irvine

x = 1 x = 4 x = 7/3 x = 1/3

22. Hero

That's bizarre. I've tried every possible way. It all comes out to the same answer

23. irvine

24. Hero
25. Hero

Exact result gives one form, alternate form gives false

26. irvine

hmmm.. this thing is so complicated :( i think im going to give up

27. Hero

Yeah, you should just guess

28. Hero

wait

29. irvine

that is what i am going to do

30. Hero

Very bizarre

31. irvine

I know I guessed 7/3 what do you think?

32. Hero

guess 1/3

33. irvine

okay that sounds better

34. irvine

35. Hero

36. irvine

idk yet im on question 16 of the test and there is 4 more i will tell you once im done

37. Hero

Okay

38. irvine

they wont show me the correct answer but it was not 1/3

39. Hero

It wasn't any of them. It was a bogus question

40. irvine

I know but it doesnt really matter anymore since i still have a good grade in the class I just hope that i dont get anymore questions like this one