Question 1047950: The sum of five numbers in an Arithmetic Progression is 25 and the sum of their squares is 165. Find the common difference.
Found 2 solutions by robertb, ikleyn: Answer by robertb(5830) (Show Source):
You can put this solution on YOUR website! ===>
===>
<===>
After expanding each term accordingly, you should get
===>
===> d = 2 or -2.
(If d = 2, the sequence is 1,3,5,7,9. If d = -2, the sequence is 9,7,5,3,1. These are two different sequences, both of which
satisfy the initial conditions.)
Answer by ikleyn(52788) (Show Source):
|
|
|