This is part of the Fibonacci sequence. The next number is 21. Look at how much each number increases and the number before it. 
1+1=2 (the number after 1 and 1) 
1+2=3 (the number after 1 and 2)
2+3=5 (the number after 2 and 3) 
So to solve we add 13+8=21
        
             
        
        
        
Answer:
JSKEJEISKJEJEJEJSJSJEJ
Step-by-step explanation:
7RHB3V BEJEJBEB 4
 
        
             
        
        
        
Answer:
D. C = 0.59x+ 275
Step-by-step explanation:
 
        
             
        
        
        
2x-13+3x-8+2x-3+2x-7+3x-1+2x+11+2x+9= (7-2)×180
16x-12=(7-2)×180
(7-2)×180 Work this out on a calculator
And then that answer=16x-12
Then you solve by adding 12 both sides and dividing by 16 both sides to get what x is.
 
        
             
        
        
        
Answer:
A. Yes
Step-by-step explanation:
the 8cm will be the hypotenuse and the 4cm and 3cm will join to create a right triangle.