7 * 38 + 3*45 - 56 
use order of operations 
(7*38) + (3*45) - 56
266 + 135 - 56
=345
        
             
        
        
        
Parallel:  the lines have = slopes.  We thus need 5/6 to equal 2/p.  then 5p must equal 12, and p = 12/5.   (answer)
Check:  Is 5/6 = 2 / (12/5)?  YES
Perp.:  The lines have slopes that are negative reciprocals of one another.
Then -6/5 = 2/p,  or
 -6      2
---- = ----
  5      p             Thus, -6p = 10, and p = -5/3   (answer)
        
                    
             
        
        
        
Answer:
   0.5 < x < 16.5
Step-by-step explanation:
The third side of the triangle must be longer than the difference of the other two sides:
   x > (8.5 -8.0)
   x > 0.5
And it must be shorter than their sum:
   x < (8.5 +8.0)
   x < 16.5
The third side must be in the range ...
   0.5 < x < 16.5
_____
These limits are a direct consequence of the triangle inequality, which requires the sum of the two shortest sides exceed the length of the longest side.
 
        
             
        
        
        
75% of 86ft would be 64.5
Hope this helps. :)