Question

find The sum of last 10 terms of AP - 8, 10, 12....126​

Answer 1

hey here ....

given a =-8.......first term

n ... number of terms = 10

so apply formula sn=n/2[ a + l ] . ......where I is the last term

..

by applying formula ...

we get

sn=10/ 2[ -8 + 126 ]..

sn=5[ 1 1 8 ]

Sn =590....

,so sum of last 10 term ' 590

Answer 2

plz refer to this attachment