Answer:
arccsc(x)=1/cos(x)
Step-by-step explanation:
 
        
             
        
        
        
Let's turn these into decimals.
so, 10.
0.75
0.50=1/2
0.40
0.20=1/5
In order from least to greatest, these would be:
0.2, 0.4, 0.5, 0.75, 10
 
        
             
        
        
        
The answer is 13, i got this by using the pythagorean theorem. a^2 + b^2 = c^2. in this case it would be 84^2 + b^2 = 85^2. then that would turn into 7056 + b^2 = 7225, subtract both sides by 7056 to get b^2 = 169, then square 169 to get 13 :)
        
                    
             
        
        
        
He buyed 240 cards because
 20
 x
 12
-----
  40
+
20
-------
240
        
                    
             
        
        
        
12.
 50/3
14.
60/11
hope this help, if you need futher help pm me