SOLUTION: how do i solve: log (base 2) 8^x = -3

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: how do i solve: log (base 2) 8^x = -3      Log On


   

Question 548913: how do i solve: log (base 2) 8^x = -3
Found 2 solutions by nerdybill, josmiceli:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
log (base 2) 8^x = -3
we can rewrite as:
log (base 2) (8)^x = -3
log (base 2) (2^3)^x = -3
log (base 2) 2^(3x) = -3
3x = -3
x = -1

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Get log base 2 on both sides of equation
Note that +-3+=+log%282%2C+1%2F8%29+, so
+log%282%2C+8%5Ex%29+=+log%282%2C+1%2F8%29+, therefore
+8%5Ex+=+1%2F8+
+8%5Ex+=+8%5E-1+
+x+=+-1+