" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
a=36
b=-2
rumus
sn= n/2(2a+(n-1)b)=s30=30/2(2(36)+(30-1)-2)
= 15(2(36)+29)-2)
=15(72)+(-58)
=15(14)
=15×14=210