Question

Find
the
sum
of
first
10 terms
Of
A.P.
7,3,-1...​

Answer 1

Sn=n/2(2a+(n-1)d)

S10=10/2(2*7+(9)(-4))

S10=5(14-36)

S10=5(-22)

S10=-110

therefore sum of first 10 terms = -11.

Answer 2

Answer:

a= 7 d = 3-7 d= -4 n=10

$sn = \frac{n}{2} 2a + (n - 1)d$

$s10 = \frac{10}{2} 2(7) + (10 - 1) - 4$

= 5 x 14 + 9 x -4

= 70 -36

= 34

hope it helps u mate