The 24th rerm of an A.P. is twice its 10th term. Show that its 72nd term is 4 time its 15th term

The 24th rerm of an A.P. is twice its 10th term. Show that its 72nd te

1.	The 24th rerm of an A.P. is twice its 10th term. Show that its 72nd term is 4 time its 15th term
Answer» a+23d=2a+18da=5d(23d-18d=5d) (i)a15=5d +14d (from i ) a15=19d (ii)now,a72=5d+71d (from i ) a72=76da72=4(19d)a72=4a15H.P. a24\xa0= 2a10a+23 d= 2(a+9d)a+23d = 2a+18d23d-18 d= 2a-a5d= aa72 =\xa04a15a+71d = 4(a+14d)5d+71 d= 4a+56d76d= 4(5d)+56d76 d= 20d+56d76d=76dhence proved