SOLUTION: 5=1.2^X what does X equal and why?

Algebra ->  Expressions-with-variables -> SOLUTION: 5=1.2^X what does X equal and why?      Log On


   

Question 446436: 5=1.2^X what does X equal and why?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+5+=+1.2%5Ex+
You can use logs to solve this.
Use the rule:
+log%28a%5Eb%29+=+b%2Alog%28a%29+
+log%285%29+=+x%2Alog%281.2%29+
Divide both sides by +log%281.2%29+
+x+=+log%285%29+%2F+log%281.2%29+
+x+=+.69897+%2F+.079181+
+x+=+8.8275
check (with calculator)
+5+=+1.2%5E8.8275+
+5+=+5.000028+
close enough