Let that certain number be 'n'
50% (n) = 39
50% ⇒ 0.5
0.5 (n) = 39
Divide both sides by 0.5
0.5n = 39
 /0.5    /0.5
n = 78.
So that certain number is actually <em><u>78! :)</u></em>
CROSS CHECK:
50% of 78
0.5 × 78
= 39
Hope this helps! :)
 
        
             
        
        
        
B. 19.8
Use the Pythagorean theorem:
14.2^ + x^ = 24.4^
201.64 + x^ = 595.36
x^ = 393.72
x = 19.84
        
             
        
        
        
Answer:
1 more cup
Step-by-step explanation:
1:10
x:50
10*5=50
1*5=5
5-4=1
1 more cup
 
        
             
        
        
        
.5 cups is equal to 1/2 cup. 
Half of 1 cup equals 4 fluid ounces.
        
             
        
        
        
We start with 20,000. Every year t, we decrease 3,000. Thus, each year the car depreciates by 3,000 every year.
B