Question

S5=55 a4 is equal to sum of first two terms find a p​

Answer 1

Answer:

S5=55

5/2(2a+4d)=55

=>5/2×2(a+2d)=55

=>a+2d=11.....(1)

a4=S2

=>a+3d=2/2(2a+d)

=>a+3d=2a+d

=>a-2d=0........(2)

Subtracting (2) from (1)

a+2d-a+2d=11-0

=>4d=11

=>d=11/4

From (2)

a=2×11/4= 11/2

AP= 11/2, 33/4, 11......