Question

First term if an ap= -5 and its last term is 45. of the sum of these terms is 120 find the no of its terms

Answer 1

● (45)+(-5)+x=120
●40+x=120
●x=120-40=80

^_^ so the value third term is of 80.

Please mark me as BRAINLEAST ANSWERS.

Answer 2

a=-5
l=45
s=120
n=?


as,
s=n/2(a+l)
120=n/2(-5+45)
120=n/2(40)
120=20n
n=6


I hope it is suitable......