80
Mental Calculation. In Public School of S. A. Rachinsky - Nikolay Bogdanov-Belsky (1895)
(upload.wikimedia.org)
Wander the gallery. Look at the art. Be polite. If you feel able please post some great art :)
I'm sure there are lots of little coincidences like this.
Taking x=10, the top of the fraction simplifies to:
5x^2^ + 20x +30
The rest of the solution is left as an exercise for the reader.