Question

If −2, a, bb, c, 14 forms an arithmetic sequence, find the values of a, b, and c.

Answer 1

a = 2, b = 6 and c = 10

Explanation:

Here arithmetic sequence is given as −2, a, b, c, 14

First term, f = -2

Fifth term, f + 4d = 14

We have

-2 + 4d = 14

d = 4

Common difference , d = 4

We know that n th term of AP is

`t_n=f+(n-1)d`

We need to find a,b,c

a = f + d = -2 + 4 = 2

b = f + 2d = -2 + 2 x 4 = 6

c = f + 3d = -2 + 3 x 4 = 10

So

a = 2, b = 6 and c = 10