Question

What is the sum of the arithmetic sequence 4, 11, 18 …, if there are 26 terms?

Answer 1

the formula for sum of 'n' terms of Arith seq is
(n/2)*(2a+(n-1)d)
a is the 1st term
d is the common difference,here d=7
just put values and calculate

Answer 2

I have to do taht 26 times:?

Answer 3

no!!
u just put the value of n as 26,a as 4 and d as 7
and that will give u sum of 26 terms directly...

Answer 4

Can you show me

Answer 5

yup ...
(26/2)*(2*4+25*7)
=13*(8+175)
can u solve further?

Answer 6

No

Answer 7

2,379 ?

Answer 8

@hartnn

Answer 9

yes :)