Evaluate the sum. 
Add the first five terms of the sequence a_{n} = n^{2 }+ 3n from Your Turn 1. 

Solve 
Step 
The first five terms are 4, 10, 18, 28, 40 
n
= 1 means
start
at 1 5 means end at 5. 

= 4 + 10 + 18 + 28 + 40 = 100 