Math, asked by nikitakherde4, 9 months ago

for an A P,a=-10,d=4.find S10​

Answers

Answered by ajay8949
4

a = -20

d = 4

n = 10

then S10 = ?

we know

 \binom{s}{ \:  \:  \: n}  =  \frac{n}{2} (2a + (n - 1)d)

=>

 \frac{10}{2} (2( - 20) + (10 - 1)4)

=> 5( -40 + 36)

=> 5 × -4

=> -20

Answered by Akay09
13

Answer:

Given a = -10 ; d = 4 n = 10

put these values in the formula

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

s10 =  \frac{10}{2} \: (2 \times  - 10 + (10 - 1)4)

= 5 (-20 + 9 ×4)

= 5 ( -20 + 36)

= 5 × 16

 = 80

this is the answer of your question. Hope you will understand it

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