Aptitude - Logarithm - Discussion
Discussion Forum : Logarithm - General Questions (Q.No. 9)
9.
If log10 5 + log10 (5x + 1) = log10 (x + 5) + 1, then x is equal to:
Answer: Option
Explanation:
log10 5 + log10 (5x + 1) = log10 (x + 5) + 1
log10 5 + log10 (5x + 1) = log10 (x + 5) + log10 10
log10 [5 (5x + 1)] = log10 [10(x + 5)]
5(5x + 1) = 10(x + 5)
5x + 1 = 2x + 10
3x = 9
x = 3.
Discussion:
14 comments Page 2 of 2.
Victor said:
5 years ago
@Saim.
We can't replace it with log2^2 because log2^2 =2log2 not 1.
We can't replace it with log2^2 because log2^2 =2log2 not 1.
Chi said:
5 years ago
One of the laws of the log is log10 10=1
log2 2=1
log5 5=1
logx x=1
@Saim.
Log 2 to the power 2 (written as log 2^2) = 2*Log2 and not 1.
log2 2=1
log5 5=1
logx x=1
@Saim.
Log 2 to the power 2 (written as log 2^2) = 2*Log2 and not 1.
Vijju said:
5 years ago
@Chi.
How log 10 10 = 1?
How log 10 10 = 1?
Gilbert Langat said:
3 years ago
@All.
According to me;
Log 5(4t+7) - log5t = 2.
According to me;
Log 5(4t+7) - log5t = 2.
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