Question

find value of y,given 3. consecutive terms of an ap as 2y+9,6y,8y+6

Answer 1

2y + 9, 6y , 8y + 6 are in Ap
     as you know, common difference of Ap is always constant 
so, ⇒ 6y - (2y + 9) = 8y + 6 - 6y
⇒ 4y - 9 = 2y + 6 
⇒ 4y - 2y = 9 + 6 = 15 
⇒ 2y = 15 ⇒ y = 15/2 
hence, y = 15/2