If 
are in A.P., prove that a, b, c are in A.P.
Given that 
are in AP.
If 
are in AP
Adding 1 to each term
are in AP
are in AP
are in AP
Divide each term by 
are in AP
Hence, a, b, c are in AP
Hence Proved.
16
If are in A.P., prove that a, b, c are in A.P.
Given that are in AP.
If are in AP
Adding 1 to each term
are in AP
are in AP
are in AP
Divide each term by
are in AP
Hence, a, b, c are in AP
Hence Proved.