" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2025 KUDO.TIPS - All rights reserved.
a3=108
a3=a1+2r
108=-12+2r
2r=108+12
2r=120
r=120/2
r=60
a2=a1+r=-12+60=48 = szukana liczba