How do you solve #2 Log (x+7) = Log 9#?

1 Answer
Özgür Özer
Dec 3, 2015

#x=-4#

Explanation:

#2*log(x+7)=log9#
#=>1/2*2*log(x+7)=1/2*log9#
#=>log(x+7)=log(9^(1/2))# (the logarithm of a second root is the logarithm of the number divided by 2)
#=>log(x+7)=log3#
#=>x+7=10^log3#
Add -7 to both sides:
#x+7-7=3-7#
#=>x=-4#

Related questions
See all questions in Logarithmic Models
Impact of this question
2124 views around the world
You can reuse this answer
Creative Commons License