Hi,
I need help to create a formula:

Invoice Amount: ( 10,000.00)
Less Fee: x
Less Insurance: ( 136.32)
Less Gross Pay: ( 1,500.00) [tax 211.79 & other 117.15 = Nett 1,171.06]

Equals Balance remaining: y
less 5% fees: y*0.05
Equals : z

Nett Salary + z should equal 82% of Invoice Amount

I need help in creating a formula for the x Fee, but as it is part of a
formula that creates y and z, a circular reference is created.

Thanks.