A basic question

edit

Hi,

I have a basic question. I don't know how to get the desired result. I am solving following problem.

var('x1','x2')
f1 = exp((2*x1+1))^2/997383793764
f2 = exp((2*x2+2)^2/8726621367521)
f = f1*f2
d = f.substitute(x1=0,x2=0)

I get an answer in the form d = e^(89324832445632473/89327467832433434646786)

How can I convert my answer (e^(89324832445632473/89327467832433434646786)) to a rational number (P/Q) that don't involve any 'e'?