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1. What is the sum of the first 19 terms of the arithmetic series?

3+8+13+18+…

 

2.  What is  equal to?

 

 

3. What is the sum of the first 75 even numbers starting with 2?

jbouyer  Feb 28, 2018
edited by Guest  Feb 28, 2018
 #1
avatar+92808 
+1

3 + 8  + 13 + 18

 

The 19th term is given by

 

3 + 5(19-1)  =  3 + 5(18)  =  93

 

And the sum is given by

 

[ 93 + 3]  (19/2) =

 

96/2  * 19 =

 

48 * 19  = 

 

912

 

The second isn't showing up for me

 

For the third, we have

 

(n) (n + 1)        where n  =  75

 

75 * 76   =

 

5700

 

 

cool cool cool

CPhill  Feb 28, 2018

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