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

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

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