You would multiply 78,125 by 5 and get I think 390,625? I think
        
                    
             
        
        
        
Answer:
300
Step-by-step explanation:
 
        
             
        
        
        
If x = 3 and y =2 then 8x+7y= 38
and 2y = 4x is correct
hope it helps :)
edit i was incorrect about second answer it would be 
2y =4x-4
        
             
        
        
        
The height of the tree is 60 meters.
Explanation:
Let the height of the tree be x. The tree casts a shadow of  meters and the distance from the top of the tree to the end of the shadow is
 meters and the distance from the top of the tree to the end of the shadow is  meters.
 meters.
The sides of the triangle are attached in the image below:
Using pythagoras theorem,

Expanding, we get,




Solving the equation using the quadratic formula  , we get,
, we get,

Simplifying, we have,



Thus, 
 and
  and  
where the value  is not possible because substituting the value
 is not possible because substituting the value  in
 in  results in negative solution. Which is not possible.
 results in negative solution. Which is not possible.
Hence, the value of x is 60.
Thus, The height of the tree is 60 meters.