Question

The sum of 1st and 9th term of an AP is 44. its 4th term is 18.what is the sum of 2nd and 8th term of this sequence?​

Answer 1

Answer:

44

Step-by-step explanation:

Answer 2

Step-by-step explanation:

a1 + a9 = 44

Using Formula, an = a+(n-1)d

[a + (1-1)d] + [a+(9-1)d] = 44

(a + 0) + (a+8d) = 44

a + a + 8d = 44

2a + 8d = 44

a + 4d = 22 __________(1)

a4 = 18

[a+(4-1)d] = 18

a + 3d = 18____________(2)

Solving eq. 1 and 2

a + 4d = 22

a + 3d = 18

= d = 4

Putting value of d in eq. 1

a + 4d = 22

a + 4×4 = 22

a + 16 = 22

a = 22 - 16 = 6

Finding 2nd term

an = a + (n - 1)d

a6 = 6 + (2-1) × 4

= 6 + 1 × 4

= 6 + 4

= 10

Finding 8th term

an = a + (n - 1)d

a8 = 6 + (8-1) × 4

= 6 + 7× 4

= 6 + 28

= 34

Sum of 2nd and 8th term

= 10 + 34 = 44