Question

in an ap 10th term is 21 and sum of the first 10 term is 120 then find the n term of the arthematic progression​

Answer 1

Answer:

a10 = 21

S10 = 120

an = a1+(n-1)d

a10 = a1+ad

a1+ad= 21  ------ -(1)

Sn = n/2 [ 2a1+(n-1)d]

S10 = 10/2[2a1+ad]

120 = 5[2a1 + ad ]

24 = 2a1+ad =24-----------(2)

Subtracting  (1) From (2)

2a1+ad = 24

a1 + ad = 21

-     -    =  3

d= 21-a1/a

21-3/9

18/9 = 2  

n term of the arthematic progression

an =a1(n-1)d

   = 3+(n-1)2

   =  3+2n-2

   = 1+2n

Hence are calculated here

Step-by-step explanation:

Answer 2

Answer:

manpreet kaur peper

qhsy6neamudsndgwb