Athena 21,718 Posted January 24, 2014 Share Posted January 24, 2014 Is anyone good with logarithms? Here's the problem: (sorry that it's sideways) I already know what most of each of those logs equal but I can't solve the whole problem. Your help would be appreciated. Link to comment Share on other sites More sharing options...
RóisÃn Dubh 3,966 Posted January 24, 2014 Share Posted January 24, 2014 http://www.wolframalpha.com/ Link to comment Share on other sites More sharing options...
AsYouLikeIt 609 Posted January 24, 2014 Share Posted January 24, 2014 I feel like this isn't the best place to ask for help in math. good luck anyways! Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 I feel like this isn't the best place to ask for help in math. good luck anyways! People have helped me before. Link to comment Share on other sites More sharing options...
youchewflopagain 260 Posted January 24, 2014 Share Posted January 24, 2014 I feel like this isn't the best place to ask for help in math. good luck anyways! Link to comment Share on other sites More sharing options...
Tokki the Awkward Potato 5,878 Posted January 24, 2014 Share Posted January 24, 2014 Can you type it out I cant see, tried to show my dad (he's an expert in math) but idk what it says clearly Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 Can you type it out I cant see, tried to show my dad (he's an expert in math) but idk what it says clearly8^(3x-1) - 7= log3243 - log81024+lne - log771 When I shrank the numbers next to "log" it means that it is a subscript thing. Also in the first part "8" is the base. "3x-1" is the exponent. Link to comment Share on other sites More sharing options...
ShawolSONEexo 2,135 Posted January 24, 2014 Share Posted January 24, 2014 sorry can't help u... math fucken hates me sooo... Link to comment Share on other sites More sharing options...
Talk 55 Posted January 24, 2014 Share Posted January 24, 2014 8^(3x-1)-7=(log base 3 of 243)-(log base 8 of 1024)+lne-(log base 77 of 1) log3243=5 log81024=10/3 lne=1 log771=0 So the right side of the equation should be 8/3. 8^(3x-1)-7=8/3 8^(3x-1)=29/3 Convert it into log form. log base 8 of 29/3=3x-1 x=about .697 Link to comment Share on other sites More sharing options...
stargazer 3,343 Posted January 24, 2014 Share Posted January 24, 2014 This is what I got Check it out. Its been a while and I was in a rush so I might have made a mistake Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 8^(3x-1)-7=(log base 3 of 243)-(log base 8 of 1024)+lne-(log base 77 of 1) log3243=5 log81024=10/3 lne=1 log771=0 So the right side of the equation should be 8/3. . Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 This is what I got Check it out. Its been a while and I was in a rush so I might have made a mistake Thank you so much! I forgot to make those logs at the end and then divide, etc. Thanks to everyone else who helped me. Link to comment Share on other sites More sharing options...
Tokki the Awkward Potato 5,878 Posted January 24, 2014 Share Posted January 24, 2014 8^(3x-1) - 7= log3243 - log81024+lne - log771 When I shrank the numbers next to "log" it means that it is a subscript thing. Also in the first part "8" is the base. "3x-1" is the exponent. showed to my dad who is over 50 years old and he didnt even know how to do it GOOD LUCK Link to comment Share on other sites More sharing options...
Jongdae 459 Posted January 24, 2014 Share Posted January 24, 2014 This is what I got Check it out. Its been a while and I was in a rush so I might have made a mistake Was about to scan what I wrote but this is exactly it lol. EDIT: Actually... what happened to your log8 in the second to last line? Shouldn't it still be 3x log 8, or am I overlooking something? Link to comment Share on other sites More sharing options...
stargazer 3,343 Posted January 24, 2014 Share Posted January 24, 2014 Thank you so much! I forgot to make those logs at the end and then divide, etc. Thanks to everyone else who helped me. np. I don't remember grade 9/10 math being this hard though Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 Was about to scan what I wrote but this is exactly it lol. EDIT: Actually... what happened to your log8 in the second to last line? Shouldn't it still be 3x log 8, or am I overlooking something? Actually that's what Im confused about right now. How did it go from "3xlog8 - log8 = log (29/3) + log 8" to this: "3x = log(29/3) + log8"? Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 np. I don't remember grade 9/10 math being this hard thoughThis is advanced 11th grade math for me. I'm just in 10th grade though. Also this is a homemade bonus. Link to comment Share on other sites More sharing options...
Jongdae 459 Posted January 24, 2014 Share Posted January 24, 2014 Actually that's what Im confused about right now. How did it go from "3xlog8 - log8 = log (29/3) + log 8" to this: "3x = log(29/3) + log8"? Continuing from stargazer's work, the step after the blue highlighted part should be: 3x log 8 = log (29/3) + log8 (the right side can be combined, making it log (232/3)) Then divide both sides by 3log8 to isolate x, thus: x = log (232/3) / 3 log(8) x is approximately = 0.697 if you're checking by calculator Link to comment Share on other sites More sharing options...
Talk 55 Posted January 24, 2014 Share Posted January 24, 2014 Actually that's what Im confused about right now. How did it go from "3xlog8 - log8 = log (29/3) + log 8" to this: "3x = log(29/3) + log8"? Not sure about the method he/she used but I ended up doing log(29/3)/log 8=3x-1. This is advanced 11th grade math for me. I'm just in 10th grade though. Also this is a homemade bonus. Algebra II? Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 Not sure about the method he/she used but I ended up doing log(29/3)/log 8=3x-1. Algebra II? Yeah Alg2/Trig Link to comment Share on other sites More sharing options...
Athena 21,718 Posted January 24, 2014 Author Share Posted January 24, 2014 Continuing from stargazer's work, the step after the blue highlighted part should be: 3x log 8 = log (29/3) + log8 (the right side can be combined, making it log (232/3)) Then divide both sides by 3log8 to isolate x, thus: x = log (232/3) / 3 log(8) x is approximately = 0.697 if you're checking by calculator That's the answer I just got except I had to round to the hundred-thousandths. Thanks! Link to comment Share on other sites More sharing options...
stargazer 3,343 Posted January 24, 2014 Share Posted January 24, 2014 Was about to scan what I wrote but this is exactly it lol. EDIT: Actually... what happened to your log8 in the second to last line? Shouldn't it still be 3x log 8, or am I overlooking something? You're right... opps Link to comment Share on other sites More sharing options...
RAE-RANG 1,386 Posted January 24, 2014 Share Posted January 24, 2014 Is anyone good with logarithms?Here's the problem: (sorry that it's sideways)I already know what most of each of those logs equal but I can't solve the whole problem. Your help would be appreciated. its gonna be long Link to comment Share on other sites More sharing options...
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