precalculus
posted by tina .
Solve the logarithmic equation. Express your solutions in exact form only.
18e^x e^x=7

18/e^x  e^x = 7
let e^x = a
18/a  a  7 = 0
18  a^2  7a = 0
a^2 + 7a  18 = 0
(a+9)(a2) = 0
a = 9 or a = 2
then
e^x = 9 > no solution
or
e^x = 2
x = ln 2