Slope is vertical change over horizontal change. Since coordinates conveniently give both the horizontal and vertical coordinates of a points, we can use the coordinates of both points to differentiate, or find the change horizontally and the change vertically between the two points.
        
             
        
        
        
Answer:
The original selling price would be $ 515.87 ( approx )
Step-by-step explanation:
Let x be the original selling price ( in dollars ),
After marking down 10%,
New selling price = x - 10% of x = x - 0.1x = 0.9x
Again after marking down 30%,
Final selling price = 0.9x - 30% of 0.9x
= 0.9x - 0.3 × 0.9x
= 0.9x - 0.27x
= 0.63x
According to the question,
0.63x = 325

Hence, the original selling price would be $ 515.87.
 
        
             
        
        
        
Answer:
Option 3 - 4 miles
Step-by-step explanation:
Given : In a city, the distance between the library and the police station is 3 miles less than twice the distance between the police  station and the fire station. The distance between the library and the police station is 5 miles. 
To find : How far apart are the police  station and the fire station?
Solution : 
Let the distance between police station and fire station be 'x'.
The distance between the library and the police station is 3 miles less than twice the distance between the police  station and the fire station. 
i.e. 
The distance between the library and the police station is 5 miles. 
i.e. 



Therefore, The police and fire stations is 4 miles apart.
So, Option 3 is correct.
 
        
                    
             
        
        
        
500 centimeters I think *sweats nervously*