" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
b = 5
Un = 295
Un = a + (n-1)b
Un = 105 + (n-1)5
Un = 105 + 5n - 5
Un = 100 + 5n
295 = 100 + 5n
295 - 100 = 5n
195 = 5n
39 = n
Sn = n/2 (a+Un)
S39 = 39/2 (105 + 295)
S39 = 19,5 (400)
S39 = 7.800