Question #03bcb

1 Answer
Mar 28, 2017

a=(2ln5+ln2)/(5ln5-2ln2)

Explanation:

Take the natural logarithm of both sides.
ln(5^(5a-2))=ln(2^(2a+1))
Use the log law log(a^b)=blog(a) to make the index a coefficient.
(5a-2)ln(5)=(2a+1)ln(2)
Expand Brackets
5aln(5)-2ln(5)=2aln(2)+ln(2)
Combine like terms on either side of equality
5aln(5)-2aln(2)=2ln(5)+ln(2)
Factorise by a on the left hand side
a[5ln(5)-2ln(2)]=2ln(5)+ln(2)
Divide both sides by 5ln(5)-2ln(2)
(a[5ln(5)-2ln(2)])/(5ln(5)-2ln(2))=(2ln(5)+ln(2))/(5ln(5)-2ln(2))
Cancelling on left hand side leaves;
a=(2ln5+ln2)/(5ln5-2ln2)

Hope that helps :)

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