Question

if nth term of an AP is 7-3n find sum of 30 terms​

Answer 1

hope this helps u

n = 1

7 - 3*1

7-3

a1=4

a2 = 7-3*2

       = 7-6

a2 = 1

a30 = 7-3*30

       = 7-90

       = -83

we will use the formula

sn= n/2[a+l]  a= first term , l = last term of the given term

     = 30/2 [4-83]

         = 15*-79

s30 =  -1185

plz mark  as brainlist answer

Answer 2

Answer:

-1185

Step-by-step explanation:

FIRST TERM=A1=7-3=4

30TH TERM= A30=7-3*30=7-90=  -83

SUM OF N TERMS =SN

HERE S30 = N/2(A1+S30)

=30/2*(4+ -83)

=-1185