Question

If l is the last term, d is the common difference and ‘s’ is the sum of n terms of an A.P. be connected by the equation 8ds = (d + 2l)2, then d = _____.

Answer 1

8ds=(d+2l)2
8ds=2d+4l
2d(4s-1)=4l
d=2l/4s-1

Answer 2

8ds = (d+2l)2
8ds = 2d+4l
8ds-2d = 4l
2d(4s-1) = 4l
d(4s-1) = 4l/2
d =2l/4s-1