SOLUTION: How would I solve for x? log(x)+log(x+15)=2 I can only get it to: log[x(x+15)]=2, is that even right? What should I do next?

Question 29882: How would I solve for x?
log(x)+log(x+15)=2
I can only get it to: log[x(x+15)]=2, is that even right? What should I do next?
Found 2 solutions by Paul, josmiceli:
Answer by Paul(988) (Show Source): You can put this solution on YOUR website!
Your first step is correct:
log[x(x+15)]=2
simplfy this
log
Apply base of 10 with the power of 2

a=, b=15, c=-100

Simplfy you get two solutions
x=-20 and x=5
Remove the negative.

Hence, the solution to the logarith equation is 5.
Paul.
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
log(x)+log(x+15)=2
log(x(x+15)) = 2
log(x^2 +15x) = 2
assume log is to the base 10
10^2 = x^2 + 15x
x^2 +15x -100 = 0
(x + 20)(x - 5) = 0
x = -20
x = +5
check
log(-20)+log(-20+15)=2
log( (-20)(-5)) = 2
log(100) = 2
10^2 = 100
checks
and
log(x)+log(x+15)=2
log(5(5+15)) = 2
log(100) = 2
10^2 = 100
checks
RELATED QUESTIONS
LOGx + LOG(x-15) = 2 Solve for x. Answer is 20 but I can not figure out how to get it. (answered by ankor@dixie-net.com)
I do not have a very large understanding of logarithms, and i can't solve the question: (answered by CharlesG2,Earlsdon)
17 = 15 + 2 log x How do I solve this? (answered by jim_thompson5910)
I tried this problem, but the answer that I got doesn't seem right to me. Any help would... (answered by Earlsdon)
I am trying to figure out how to find x in: -4log base 2 (-2x)=-8 I know that it can... (answered by ewatrrr)
How do I solve this? Thank you!!... (answered by nerdybill)
Hi, this is my second time asking a question....both were on logarithms :( Solve for... (answered by Alan3354,MathTherapy)
I get different answers depending on how I simplify the expression {{{5^(3log(25,a))}}}.... (answered by Alan3354,moyshekapoyre,MathTherapy)
How do you solve this problem. And please explain because I am having trouble. log x... (answered by ankor@dixie-net.com)