Answer:
3x - 20 = 13
Step-by-step explanation:
1. The word is signals the equal sign. 
The difference of three times a number and 20 = 13
2. The word difference signals subtraction. 
3. The phrase a number sigals that the number is unknown, so a variable should be used. In this case, I'll use x. 
4. Three times that number = 3x. 
The difference = subtraction.
3x-20=13
 
        
                    
             
        
        
        
When the transverse axis is horizontal, a hyperbola centered at (h,k) has formula (x-h)^2/a^2-(y-k)^2/b^2=1. Plug in h=2, k=1, the formula is (x-2)^2/a^2-(y-1)^2/b^2=1 for some a,b. If the transverse axis is vertical, the formula is (y-h)^2/a^2-(x-k)^2/b^2=1, and (y-2)^2/a^2-(x-1)^2/b^2=1 in our case.
        
             
        
        
        
Probability = (total 22-29 age bracket + number of not respond and aged 18-                             21) / total people
                 = (284+14) / 376
                 = 0.792
                 = 0.79