log105+log10(5x+1)=log10(x+5)+1 হলে x এর মান কত?

log₁₀5+log₁₀(5x+1)=log₁₀(x+5)+1 হলে x এর মান কত?

A 1

B 3

C 5

D 9

Solution

Correct Answer: Option B

log₁₀5+log₁₀(5x+1)=log₁₀(x+5)+1
or,log₁₀5+log₁₀(5x+1)=log₁₀(x+5) +log₁₀10
or,log₁₀5×(5x+1)=log₁₀(x+5)×10
or,log₁₀25x+5=log₁₀10x+50
or,25x+5=10x+50
or,15x=45
∴ x=3

Solution

Practice More Questions on Our App!

Related Topics