I built a quick table using your characters to try this... Only B, F, N and a ID field.
To get "R" I used this in a query:
SELECT ((1/[N])+([F]/1200))*[B] AS 1, Table1.ID
FROM Table1;
To get "B" I used this:
SELECT R.ID, Table1.F, Table1.N, R.[1], [1]/((1/[N])+([F]/1200)) AS 2
FROM Table1...