Posted by Lindsay on .
Find the sum of the first 40 terms of the arithmetic sequence. 19, 24, 29, 34

arithmetic 
bob,
dude why do you put su hard question on here and nobody can do it

arithmetic 
Bosnian,
In wikipedia type
"Arithmetic progression"
you wil find everythink about Arithmetic progression
Sn=sum of numbers
Sn=(n/2)*[2a1+(n1)*d]
In this case:
n=40
a1=19
d=5
S40=(40/2)*[2*19+(401)*5]=20*(38+39*5)=20*(38+195)=20*233=4660