Discriminant = b^2 - 4ac
a = 4
b = 16
c = 16
16^2 - 4(4 x 16)
256 - (4x64)
256 - 256 = 0 
Therefore it only has one root
 
        
             
        
        
        
Answer:
Step-by-step explanation:
 
        
             
        
        
        
Answer:
4851 ways
Step-by-step explanation:
The fish have 3 choices. They can make it above, below, or though the pipe. Keep in mind there are 100 fish total:
group 1 + group 2 + group 3 = 100
If we keep group 3 (the fish that swim below the pipe) constant, say 1, and increment the other two (group 2 starting off at 1) we find 98 possibilities.
    98     +      1        +      1        = 100,
    97      +     2        +      1        = 100,
    96      +     3        +      1       =  100
         .           .            . 98 possibilities
Now we take group 1 as one greater (1 + 1 = 2) and then start incrementing group 2 starting from 1 as done before. So 97 + 2 + 1 = 100. Followed by 96 + 3 + 1, 95 + 4 + 1...97 possibilities
If we continue this pattern, we have 98 + 97 + 96... + 1 total possibilities to partition this school of fish. 
98 + 97 + 96... + 1,
Sum = n(n + 1)/2 = 98(98 + 1)/2 = 98(99)/2 = 4851
 
        
             
        
        
        
Answer:
Part A. At least 6 hours
Part B.  In less than 2.5 hours Elijah will be behind Mercedes
Part C.  In more than 2.5 hours Elijah will be ahead Aubrey
Step-by-step explanation:
D = distance
v =speed 
t = time
Formula connecting D, v and t:

Part A. 
Steve's speed: 
Distance: at least 21 miles
Time: unknown, so
![3.5\cdot t\ge 21\\ \\35t\ge 210\ [\text{Multiplied by 10}]\\ \\t\ge \dfrac{210}{35}\\ \\t\ge \dfrac{30}{5}\\ \\t\ge 6](https://tex.z-dn.net/?f=3.5%5Ccdot%20t%5Cge%2021%5C%5C%20%5C%5C35t%5Cge%20210%5C%20%5B%5Ctext%7BMultiplied%20by%2010%7D%5D%5C%5C%20%5C%5Ct%5Cge%20%5Cdfrac%7B210%7D%7B35%7D%5C%5C%20%5C%5Ct%5Cge%20%5Cdfrac%7B30%7D%7B5%7D%5C%5C%20%5C%5Ct%5Cge%206)
It would take Steve at least 6 hours to walk at least 21 mi on Day 1.
Part B. 
Mercedes's speed: 
Elijan's speed: 
Elijan's Distance walked:  miles
 miles
Mercedes's Distance walked:  miles
 miles
Time: x hours
Mercedes is 2 miles ahead, so

Elijan will be behind when
 
In 2.5 hours Elijan will catch up Mercedes, and in less than 2.5 hours Elijah will be behind Mercedes.
Part C. 
Aubrey's speed: 
Elijan's speed: 
Elijan's Distance walked:  miles
 miles
Aubrey's Distance walked:  miles
 miles
Time: x hours
At the beginning of Day 3, Elijah starts walking at the marker for Mile 42,  and Aubrey starts walking at the marker for Mile 42.5.

Elijan will be ahead of Aubrey when
 ![D_E>D_A\\ \\42+3.2x> 42.5+3x\\ \\3.2x-3x>42.5-42\\ \\0.2x>0.5\\ \\2x>5\ [\text{Multiplied by 10}]\\ \\x>\dfrac{5}{2}\\ \\x>2.5\ hours](https://tex.z-dn.net/?f=D_E%3ED_A%5C%5C%20%5C%5C42%2B3.2x%3E%2042.5%2B3x%5C%5C%20%5C%5C3.2x-3x%3E42.5-42%5C%5C%20%5C%5C0.2x%3E0.5%5C%5C%20%5C%5C2x%3E5%5C%20%5B%5Ctext%7BMultiplied%20by%2010%7D%5D%5C%5C%20%5C%5Cx%3E%5Cdfrac%7B5%7D%7B2%7D%5C%5C%20%5C%5Cx%3E2.5%5C%20hours)
In 2.5 hours Elijan will catch up Aubrey, and in more than 2.5 hours Elijah will be ahead Aubrey.
 
        
             
        
        
        
Double
from initial amont of P to final amount of 2P
so
2P=P(1.071)^time
divide both sides by P
2=1.071^time
take the ln of both sides
ln2=timeln1.071
divide both sides by ln 1.071
(ln2)/(ln1.071)=time needed
using calculator
10.1052=time needed
about 10.1 hours