It's a bit difficult to decypher it since
- it's not the most readable handwriting
- looks like not quite contemporary Bulgarian
- there are some spelling errors
- not sure if some ends are not cut off in the pic
I can understand some bits, but not the whole of it.
The things below are the bits I am 80-90% sure I get.
И с това поле
мерака за борба ---- wish for struggle
надежда среща ----- meets hope
да вършим* прилежно. ----- to do diligently
Труд и ревностна сполука ----- Work and zealous success ?
What book did you find this in?
* I can't see the "ш" but I think that's the word.
Защо да харчим пари, които нямаме, за да купим неща, които не са ни нужни, така че да впечатлим хора, които не харесваме?
I don't even remember what standard deviation is.
BezierCurve: It's some important part of sadistics, I believe.