You are here:

Advanced Math/College Algebra

Advertisement

Expert: Sherry Wallin - 4/28/2011


Question
2log(x+5)=log27+log3

Answer
Kristan~

There are probably a lot of ways to answer this question and here is just one way:
2log(x+5) = log(x+5)^2
and
log 27 + log 3 = log 3^3 + log 3 = 3log 3 + log 3 = 4log 3 = log 3^4
so 2log(x+5)=log27+log3 =>
log(x+5)^2 = log 3^4
(x+5)^2 = 3^4
x^2+10x+25 = 81
x^2+10x-56 = 0
(x+14)(x-4) = 0
x = 4 since x ~=-14

Math Prof

Advanced Math

All Answers

Answers by Expert:

Ask Experts

Volunteer

Sherry Wallin

Expertise

I can answer most questions up through Calculus and some in Number Theory and Abstract Algebra.

Experience

I have had my Bachelor's Degree since 1987 and have been a teacher since 1988. I earned my Masters Degree in Mathematics May 2010. I have been teaching at the same community college since 2002.

Education/Credentials
I have taught 12 years at the community college level, medical college, and technical college as well as a high school instructor and alternative education instructor and charter school instructor.

Awards and Honors
Master's GPA 3.56 Bachelor's GPA 3.34 Post grad work not degree related GPA 4.0

©2012 About.com, a part of The New York Times Company. All rights reserved.