logarithms!


by moe11
Tags: logarithms
moe11
moe11 is offline
#1
Nov19-08, 05:29 PM
P: 8
1. The problem statement, all variables and given/known data
12^x=4X8^(2x)

Big X= multiplication sign
little x= unknown

i simply cannot figure this out. Any help please?

2. Relevant equations
4.6X1.06^(2x+3)=5X3^(x)
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Dick
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#2
Nov19-08, 05:40 PM
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Use logarithms! Isn't that your title? Take the log of both sides and use the rules of logarithms to simplify. What do you get?
moe11
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#3
Nov19-08, 05:56 PM
P: 8
Quote Quote by Dick View Post
Use logarithms! Isn't that your title? Take the log of both sides and use the rules of logarithms to simplify. What do you get?
i wouldnt post this if i could do it as easily as you said. Can you explain? Thats why i'm here.

Dick
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#4
Nov19-08, 06:01 PM
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logarithms!


log(12^x)=log(4*8^(2x)). That wasn't so hard. Now simplify it. Use rules of logarithms like, log(a*b)=log(a)+log(b), log(a^b)=b*log(a).
HallsofIvy
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#5
Nov19-08, 06:06 PM
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Your equation is 12[sup]x=(4)8[sup]2x[sup].

Since you titled this "logarithms", Dick assumed you knew some basic rules of logarithms. Take the logarithm of both sides: log(12x= log((4)8[sup]2x[sup])

Now use the fact that log(ab)= log(a)+ log(b) and that log(ax)= x log(a).


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