129 degrees you just add DCE and ECF together
        
                    
             
        
        
        
Answer: 4 1/10g^5+5 1/4
Step-by-step explanation:
 
        
             
        
        
        
Multiply the numerator and denominator by the whole number. you'll most likely get an improper fraction though. 
        
             
        
        
        
Answer:
B
Step-by-step explanation:
Note the common difference between consecutive terms of the sequence.
d = 16 - 12 = 20 - 16 = 4
This indicates the sequence is arithmetic with sum to n terms
 =
 =  [2a₁ + (n - 1)d ]
 [2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Here a₁ = 12 and d = 4, thus
 =
 =  [ (2 × 12) + (41 × 4) ]
 [ (2 × 12) + (41 × 4) ]
                           = 21( 24 + 164) = 21 × 188 = 3948 → B