Question

Given the AP as 40 + 37 + 34 + … find S10, tn and expression for Sn.​

Answer 1

Step-by-step explanation:

a= 40

d= 37- 40= -3

an= a+ (n-1) d

a10= 40+ (10-1) (-3)

a10= 40+ (9)(-3)

a10= 40+ (-27)

a10= 40- 27

a10= 13

Sn= n/2 (a+l)

S10= 10/2 (40+13)

S10= 5 (53)

S10= 265

Hope my answer helps you.