math
posted by lindsay on .
Solve the equation
3^2x  12 x 3^x + 27 = 0

let 3^x = y
so we get
y^2  12y + 27 = 0
(y3)(y9) = 0
y = 3 or y = 9
then
x^2 = 3 or x^2 = 9
x = ± √3 or x = ± 3
btw, in something like 12 x 3^x , do not use x as a multiplication sign, especially if you have a variable x
either say just 12(3^x) or say 12*3^x