This v divider is easy with voltage known

This voltage divider let's us chose resistance according to our requirement so from 50v we need 2.5v we 50-2.5=47.5divide by 2.5=19r 2 should be 19 times bigger then r1 so if we let r1 1k and r2 19k so we get from vcc and mid point of resistor 2.5v