dany jest ciąg arytmetyczny w którm s1=3 s3=18 jle jest równy 45 wyraz tego ciągu i różnica r tego ciągu
S1 = a1 = 3
S3 = a1 + a2 + a3 = a1 + (a1 + r) + ( a1 + 2 r) = 3 a1 + 3r = 18
zatem
3*3 + 3r = 18
3r = 18 - 9 = 9
r = 3
=====
an =a1 + ( n-1)*r
==================
a45 = a1 + 44 r= 3 + 44*3 = 3 + 132 = 135
====================================
" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
S1 = a1 = 3
S3 = a1 + a2 + a3 = a1 + (a1 + r) + ( a1 + 2 r) = 3 a1 + 3r = 18
zatem
3*3 + 3r = 18
3r = 18 - 9 = 9
r = 3
=====
an =a1 + ( n-1)*r
==================
zatem
a45 = a1 + 44 r= 3 + 44*3 = 3 + 132 = 135
====================================