SOLUTION: I am stuck on how to solve the problem 6^-3x=15 I do not understand logrithms at all. Thank you for your help. LC

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: I am stuck on how to solve the problem 6^-3x=15 I do not understand logrithms at all. Thank you for your help. LC      Log On


   

Question 534786: I am stuck on how to solve the problem 6^-3x=15
I do not understand logrithms at all.
Thank you for your help.
LC
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose I say +z+=+-3x+
Then
+6%5Ez+=+15+
I know that
+6%5E1+=+6+
+6%5E2+=+36+
So, z is somewhere between 1 and 2
and,
+1+=+-3x+
+x+=+-%281%2F3%29+
+2+=+-3x+
+x+=+-%282%2F3%29+
so, x must be between -(2/3) and -(1/3)
You could find the answer by trying
+6%5E1.1+
+6%5E1.2+
etc
on a calculator until you get very, very close to 15