Question

find the sum of first 10th term of the AP X - 8 x - 2 and X + 4​

Answer 1

This is the your answer

Answer 2

By question,

x-8, x-2 and x+4 are in AP

Their common difference (d) = 6

a = x-8

n = 10

Now,

S10 = n/2 * [2a + (n-1)d]

= 10/2 * [2(x-8) + 9*6]

= 5 [ 2x - 16 + 54]

= 5 [ 2x + 38]

= 10x + 190