Well, ok, we have:
log_2(x + 4) - log_2(x - 3) = 3
First, we'll use one of the properties of logs:
loga - logb = loga/b
So, we have:
log_2{(x + 4)/(x - 3)} = 3
Now, what that expression above says is: "The power you put on 2 to get (x + 4)/(x - 3) is 3." So, we rewrite it as such:
2^3 = (x + 4)/(x - 3)
8(x - 3) = x + 4
8x - 24 = x + 4
7x - 24 = 4
7x = 28
x = 4
There you go.
2007-12-27 14:59:41
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answer #1
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answered by Eolian 4
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To do those, keep in mind the operation conversion that occurs once you adjust c= base^potential to a logarithm. The log version is log(base)c=potential So permit's attempt #6. this is the log version of (x+4)^3 = one hundred twenty five. So what selection cubed is one hundred twenty five. situations UP, the respond is 5. So x+4=5 and x=a million.
2016-10-20 03:07:45
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answer #2
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answered by ? 4
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Okay. I'm assuming you know basic log properties.
When you've got log subtraction with the same base, it turns into division. So, you'd end up with:
log(base 2) (x+4/x-3)=3
Now, by changing the equation into normal exponent form, you should get:
2^3=x+4/x-3
8=x+4/x-3
8x-24=x+4
7x=28
x=4
2007-12-27 15:00:47
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answer #3
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answered by Anonymous
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log(base2) (X+4) - log (base2) (x-3) =3
log(base2)[(x + 4)/(x - 3)] = 3
2^3 = (x + 4)/(x - 3)
8(x - 3) = (x + 4)
8x - 24 = x + 4
8x - x = 24 + 4
7x = 28
x = 4 ANS
Hope I help you.
teddy boy
2007-12-27 15:31:33
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answer #4
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answered by teddy boy 6
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Let log be log to base two in the following:-
log (x + 4) - log (x - 3) = 3
log [ (x + 4) / (x - 3) ] = 3
(x + 4) / (x - 3) = 2 ³
(x + 4) / (x - 3) = 8
x + 4 = 8x - 24
28 = 7x
x = 4
2007-12-27 22:20:13
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answer #5
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answered by Como 7
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formulae:
1) log(basex)y = z => y = x^z
2) logx - logy = log(x/y)
log(base2)(x+4) - Log(base2)(x-3) = 3
=>log(base2) [(x+4)/(x-3)] = 3
=>(x+4)/(x-3) = 2^3 = 8
=>x+4 = 8x - 24
=> x = 4
(Ans)
2007-12-27 15:17:03
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answer #6
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answered by lalalala 2
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okay, combine the left hand side to make one log
log(base 2) [(x+4)/(x-3)] = 3
now, set the right hand side, 3, as a log of base 2
log(base 2) [(x+4)/(x-3)] = log(2^3)
and now you can cancel the logs on both sides, leaving you with a nice, clean, solvable equation.
x+4/x+3 = 2^ 3
you can do the rest :P
2007-12-27 15:33:25
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answer #7
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answered by Anonymous
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2^log(base2)(x+4) - 2^log(base2)(x-3)=2^3
(x+4)-(x-3)=8
7=8
No solution!
2007-12-27 14:56:22
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answer #8
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answered by Thenardier never wins 2
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log(x) - log(y) = log(x/y)
log((x+4)/(x-3)) = 3
(x+4)/(x-3) = 2^3 = 8
28 = 7x
4 = x
2007-12-27 14:59:20
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answer #9
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answered by dooner75 3
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log2(x+4)/(x-3)=3
8=(x+4)/(x-3)
8x-24=x+4
7x=28
x=4
2007-12-27 15:21:09
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answer #10
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answered by someone else 7
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