the common difference of the ap 1/p, 1-p/p, 1-2p/p

 Solution

Given sequence 1/p ,1-p/p, 1-2p/p

We know that common difference is denoted by d. 

So d=second term - first term 

      d=an -a(n-1) (proof video) 

d=(1-p) /p -1/p

d=1-p-1/p

d=-p/p

d=-1

Or

d=third term -Second term

d=(1-2p)/p -(1-p)/p

d={(1-2p)-(1-p)} /p

d=(1-2p-1+p) /p

d=-p/p

d=-1 

hence d=-1 proved 

d=(-p