Question

Logarithms
Solve 6^2x-2(6^x)-15=0

Answer 1

Say m=6^x
M^2-2m-15=0
(m-5)(m+3)=0
m=5 or -3
So
6^x= 5 or -3
C

Answer 2

\[x= {\log_{6} 5}\] or\[{ \log_{6}-3}\]

Answer 3

thank you!

Answer 4

Beware..the second answer is extraneous. You can't take a log of a negative value. (Think about it: 6 to what power becomes suddenly negative?)

Answer 5

Ahh yeah thanks