Sigma Notation

Evaluate:  $\sum_{i=1}^420$  

Evaluate:  $\sum_{i=1}^7-9$  

Evaluate:  $\sum_{i=1}^{12}-3$  

Consider the sequence: 

S={1, 2, 4, 8, 16, 32, ...}

Evaluate: $\sum_{i=3}^7\frac{1}{2}a_i$  

Consider the sequence: {8, 6, 4, 2, 0, -2, -4,...} 

Evaluate: $\sum_{i=4}^{10}5a_i$  

Consider the sequences,

S={1, 2, 4, 8, 16, 32,...} 

and P={1, 1/2, 1/4, 1/8, 1/16,...}
Evaluate:
 $\sum_{i=5}^6a_i+b_i$  

Consider the sequences,

S={2,4,6,8,10,...} and P={0,1,4,9,16,...}
Evaluate: 
 $\sum_{i=1}^3a_i+b_i$  

Consider the sequences,

S={2,4,6,8,10,...} and P={0,1,4,9,16,...}
Evaluate: 
 $\sum_{i=3}^6a_i-b_i$  

Consider the sequences,

 S={-2,-4,-6,-8,-10,...} and P={0,1,4,9,16,...}

Evaluate: 
 $\sum_{i=1}^5a_i-b_i$  

Consider the sequence,

 S={2,4,6,8,10,...} 

Evaluate: 
 $\sum_{i=1}^3a_i+\sum_{i=4}^5a_i$