+0  
 
0
112
1
avatar+3413 

#14 Help

NotSoSmart  Mar 16, 2018
 #1
avatar+89781 
+2

14.

 

The first term is  3(1)  - 4  =   -1    and the last is  3(18) - 4  = 50

So....the sum is

 

[ -1 + 50 ] (18/2)  =  49 * 9   =  441 

 

 

15.  The first term is  3(1)  - 3  =   0     and the last is  3(10) - 3  =  27

So  the sum is  [ 0 + 27 ] * (10/ 2)  =  27 * 5   =  135

 

 

 

cool cool cool

CPhill  Mar 16, 2018

34 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.