Can someone solve the following for me

I need someone to show me how to solve for t, I am having quite a lot of trouble with it:

1.2n=(n-Am)*e^(Bt) + (n+Am)*e^(-Bt)

If you could go through step by step it would be great, I will select a best answer as soon as possible. Thanks.

Let E = e^(Bt). then 1/E = e^(-Bt)

1.2n = (n - Am) e^(Bt) + (n + Am) e^(-Bt)

1.2n = (n - Am) E + (n + Am) (1/E)

1.2En = (n - Am) E^2 + (n + Am)

(n - Am) E^2 - 1.2nE+ (n + Am) = 0

E = [ 1.2n ± √(1.44n^2 - 4(n - Am)(n + Am)) ] / ((2(n - Am))

E = [ 1.2n ± √(1.44n^2 - 4n^2 + A^2 m^2)) ] / ((2(n - Am))

E = [ 1.2n ± √(A^2 m^2 - 2.56n^2)) ] / ((2(n - Am))

e^(Bt) = [ 1.2n ± √(A^2 m^2 - 2.56n^2)) ] / ((2(n - Am))

t = (1/B) ln( [ 1.2n ± √(A^2 m^2 - 2.56n^2)) ] / ((2(n - Am)) )

Be equal to the problem do the same thing to each side. Simplify for n