Question

in an AP second term is 8, fifth term is 17. Find 19th term

Answer 1

Hello friend

Good evening

⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐

Given that

=> T2 = 8

=> a + d = 8

=> a = 8 - d...........( i )

And

=> T5 = 17

=> a + 4d = 17

From ( i ) eq.

=> 8 - d + 4d = 17

=> 3d = 17 - 8

=> d = 9/ 3

=> d = 3

So we have,

=> a = 8 - d

=> a = 8 - 3

=> a = 5

And d = 3

So the t 19 nineteenth term = a + 18d

=> 5 + 18 x 3

=> 5 + 54

=> 59

So the nineteenth term is 59.

⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐

Answer 2

a+d=8 -(1)
a+4d=17 -(2)
subtract equation 1 and 2
we will get d=3
a+d=8
a+3=8
a=5
an=a+(n-1)d
a19=5+(19-1)3
=5+18×3
=5+54
=59
Hence the 19th term is 59.