Let S be the sum of the first 9 terms of the series: x+ka + x^2+(k+2)a + x^3+(k+4)a + x^4+(k+6)a + where a 0...

Question

Let S be the sum of the first 9 terms of the series: x+ka + x^2+(k+2)a + x^3+(k+4)a + x^4+(k+6)a + where a 0 and x 1. If S= x^ 10 -x+45a(x-1) x-1 , then k is equal to :

Accepted Answer

(C)

JEE Main 2020 Mathematics question

Solution