The answer would be 42
42*3 = 126
126+5 = 131
3(n)+5=131 
3(n)+5 -5= 131-5
3(n)=126
3(n)/3= 126/3
n= 42
        
             
        
        
        
Answer:
22.84, 5.83
Step-by-step explanation:
Pythagoras theorem states that: a^2+b^2=c^2
So, for red triangle, it will be: 9^2+21^2=b^2
81+441=b^2
522=b^2
square root of 522=b
22.84=b
For purple one, 
3^2+5^2=a^2
9+25=a^2
34=a^2
square root of 34=a
5.83=a
 
        
             
        
        
        
Answer:
42.194988
Step-by-step explanation:
There are 42.194988 km in 1 marathon
 
        
             
        
        
        
Answer:
B. 3
Step-by-step explanation:
Since you are given that chord AB's length is 8 and is bisected by segment XC, that means segment BC's length is 4 and ∠XCB is a right angle. From there, we use Pythagorean Theorem to solve for length XC:
4² + b² = 5² (Or remember 3-4-5 makes a Pythagorean triple)
c = √(5²-4²)
c = 3
 
        
             
        
        
        
Answer:
160 2p coins
Step-by-step explanation:
3/8 x 640 = 240 = 1p coins
240 = 5p coins
240 + 240 = 480
640 - 480 = 160