+0  
 
0
108
1
avatar

Express the sum 10 + 11 + 12 + ... + n in terms of n.

 Dec 13, 2020
 #1
avatar+117546 
+1

Sum = 

 

[ First term + Last term ]   ( Number of Terms ) / 2

 

   [ 10 + n ]  * ( n - 10 + 1)  / 2  = 

 

[ 10 + n ]  *  ( n - 9)  / 2

 

 

cool cool cool

 Dec 13, 2020

66 Online Users

avatar
avatar
avatar
avatar