Answer:
67 mm
Step-by-step explanation:
use area of a trap formula: 
b1+b2 /2*h
b1=base 
b2=base
h=height
in our case it was, 8.2+5.2/2*10
67
 
        
             
        
        
        
Answer:
sqrt(-8x+5)
Step-by-step explanation:
(5-8x)
-----------------
sqrt(-8x+5)
We need to rationalize the denominator
(5-8x)               sqrt(-8x+5)
----------------- * ---------------
sqrt(-8x-5)         sqrt(-8x+5)
(5-8x)               sqrt(-8x+5)
----------------- * ---------------
(-8x+5)
The first term cancels
sqrt(-8x+5)