Question

Find the sum
given
of
51 terms, whose 2nd and & 3rd terms are 14 and 18 respectively​

Answer 1

Answer:

5610

Step-by-step explanation:

given

a + d = 14

a + 2d = 18

from these two eq. we can easily find a and d

a = 10

d = 4

now sum of n terms

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

putting the values of a,d and n = 51

S = 51/2(20 + 50*4)

S = 51/2(220)

S = 51*110

S = 5610

Please mark me as brainliest if it is correct.

Answer 2

Step-by-step explanation:

a2=14, a3=18

common difference=a3-a2=18-14=4

now,

a2=a+d=14

a+4=14

a=14-4

a=10

now, sum of 51 terms

{51(2a+(50)d)}/2

{51(20+200)}/2

{51×220}/2

51×110=5610

therefore the sum of 51 term is 5610