Transposition of formula(inductance)

[NUMB_NUTS]

Hi i hope you can help me?
My question is:

Given the relationships:

B/h = U, H = IN/l and L = N x dphi/dI {ie, L = N x change in phi/change in I}.

show that the inductance of the coil is:

L = Nsquared/S Where S = l/uA ??

.l is lower case L for length
.U is absolute permeability.
your help would be most welcome please many thanks

 

[big man]

Have you got any ideas on how you might find the equation for the inductance of a solenoid?