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Logarithm 8) if 2/ log20-1 = logbA, find the value of A and B

Logarithm 8) if 2/ log20-1 = logbA, find the value of A and B-example-1
User Christopher Martin
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1 Answer

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26 votes

Hello there. To solve this question, we'll have to apply some logarithm properties to rewrite the number and determine the values of A and B.

Given


(2)/(\log (20)-1)=\log _B(A)

We can rewrite the expression in the denominator using the following rule:


\log _C(a)-\log _C(b)=\log _C\left((a)/(b)\right)

Remember that we write log for a logarithm with base 10 and ln for a logarithm with base e, thus we have:


\log (20)-1=\log (20)-\log (10)=\log \mleft((20)/(10)\mright)=\log (2)

And rewrite the expression in the numerator using the property:


\log _C(a^b)=b\cdot\log _C(a)

Therefore we have:


2=2\cdot1=2\cdot\log (10)=\log (10^2)=\log (100)

Finally, we use the following property to find A and B:


(\log_C(a))/(\log_C(b))=\log _b(a)

We get that:


(\log(100))/(\log(2))=\log _2(100)

And this is equal to:


\log _2(100)=\log _B(A)

If only A = 100 and B = 2.

User Jason Grife
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