He circumference of a circle<span> is equal to the diameter times pi. So, let's look at </span>what happens<span> if you double the </span>radius<span> of a </span>circle<span> -- say from 2 to 4. The area will go from 12.56 to 50.24. This means that it has </span>quadrupled<span>.</span>
        
                    
             
        
        
        
Answer: A or D i think sorry if wrong but a i think
Step-by-step explanation:
but The distance between A and B = |B - A|
We have -12 and -1.
Substitute:
|-1 - (-12)| = |-1 + 12| = |11| = 11
Answer: 11 units
 
        
             
        
        
        
Answer:
$ 1.725
Step-by-step explanation:
4 Pack of coffee = $ 6.90
1 Pack of coffee = $ 6.90 / 4 = $ 1.725
( The word per means " 1 " )
 
        
                    
             
        
        
        
X(x+2)-(1/3)x=150
x²+2x-(1/3)x-150=0
x²+(5/3)x-150=0
3x²+5x-450=0
this does not produce an integer, because b²-2ac=5²+4*3*450=5425, and √5425=73.6546 is not an integer.
Please double check your question. 
        
             
        
        
        
Answer
Find out the  how far into the country does he go.  
To proof
Let us assume that the total diatance travelled into the country be x .
Formula

As given
A cyclist rides into the country at an average speed of 10 miles per hour. When his bicycle gets a flat tire,
 he walks it back at an average speed of 3 miles per hour.
 If he returns home 6 and a half hours after he starts i.e the total time including the bike time and walk time of the cyclist be 6.5 hours.
Than the equation becomes

L.C.M of (10,3) = 30
Than the equation becomes
3x +10x = 195
solving
13x = 195

x = 15 miles into the country
Hence proved