Given that and ,
use the properties of the summation notation to find the value of .
Remember the properties of summation notation for two sequences and , where and :
Firstly we apply the rule of addition and subtraction (rule 2), then we apply the the rule of multiplication by a constant (rule 1).
Following this we apply the rule about changing the limits (rule 3).
Now we can apply the given formulas to calculate the sum of the series.