Question

The sum of 11 terms of -7, -2,3,8....is n*22 then n?​

Answer 1

Step-by-step explanation:

an =a+(n_1)d

22=_7+(10_1)5

22=_7+50

22=43

43-22=21

Answer 2

Answer:

Step-by-step explanation:

AP= -7,-2,3,8.....

given: S₁₁= n*22.......(1)

n=?

a= -7

d= -2-(-7) = 5

S₁₁ = n/2 * ( 2a + (n-1)*d )

S₁₁= 11/2 * ( 2(-7) + (11-1)*5 )

   = 11/2 * ( -14 + 50 )

   = 11/2 * (36)

   = 11 * 18 = 198//

from equation (1)

n*22 = 198

n = 198/22 = 9//

therefore n=9//