Math problem... solving for a variable thats an exponent

[Myst]

Umm so Im taking an actuarial science course for the spring
I cant for the life of me remember how to do this cause its been so long

how do you solve
1.08^-n + 1.08^-2n = 1

[fallenmuffin]

irc://irc.efnet.net/math

[gooddomains]

1+1=3 :-)

[deef-thp]

-48.830373630755

[AmigoPorn]

1.08^-n + 1.08^-2n = 1

1 + 1.08^-n = 1 ( 1.08^n )

-1.08^n + 1.08^-n + 1 = 0

-1.08^n + 1 / ( 1.08^n ) + 1 = 0

-1.08^2n + 2 = 0

1.08^2n = 2

2n = log 2 / log 1.08

2n = 9.006468342

n = 4.503234171

[dave_w]

1.08^-n + 1.08^-2n = 1

1 + 1.08^-n = 1 ( 1.08^n )

-1.08^n + 1.08^-n + 1 = 0

-1.08^n + 1 / ( 1.08^n ) + 1 = 0

-1.08^2n + 2 = 0

1.08^2n = 2

2n = log 2 / log 1.08

2n = 9.006468342

n = 4.503234171