Step-by-step explanation:
b can be used to check her score
Answer:
Step-by-step explanation:
1) x² + 6x + 11 = 0
a = coefficient of x² = 1
b = coefficient of x = 6
c = Constant = 11
Roots = (-b ± √b² - 4ac)/2a

Roots = 

2) 2x² - 16x = 50
Divide the whole equation by 2
x² - 8x = 25
Divide the coefficient of x (i. e 8 ) by 2 = 8/2 = 4, Now add 4 to both sides of the equation
x² - 8x + 4 = 25 + 4
x² - 2*4*x + 2² = 29
(x - 2)² = 29
Take square root both side

Answer:
recommended value of iron is 
Step-by-step explanation:
In 3/4 cup of oatmeal, that is 1/10 of the recommended daily value of iron
The ratio of cup of oatmeal to the value of iron is

Let x be the recommended value of iron for 1 cup of oatmeal
Make a proportion


cross multiply



recommended value of iron is 2/15
Answer:
25,31,37
Step-by-step explanation:
n should be positive integer number. The three numbers in both sequences have different term number n but same value. We can equalize each nth term in the question to "a" which represents one of the three numbers.
a=2n-1, then n=(a+1)/2
a=3n+1, then n=(a-1)/3
remember the two n above are different but both should be positive integer. That means, we have to find the "a" number that gives me an integer n for the first equation. The possible numbers between 20 to 40 are 22,25,28,31,34,37,40.
The possible numbers for the second equation are 21,23,25,27,29,31,33,35,37,39.
Now find the common numbers between the two sets above. They are 25,31,37
Answer:
The number of rainfalls is 
The answer to the second question is no it will not be valid this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the pH reading) from one rainfall will make the experiment invalid.
Step-by-step explanation:
from the question we are told that
The standard deviation is 
The margin of error is 
Given that the confidence level is 95% then we can evaluate the level of significance as



Next we will obtain the critical value of
from the normal distribution table , the value is 
Generally the sample size is mathematically represented as
![n = [\frac{Z_{\frac{\alpha }{2} * \sigma }}{ E} ]^2](https://tex.z-dn.net/?f=n%20%20%3D%20%20%5B%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%2A%20%20%5Csigma%20%7D%7D%7B%20E%7D%20%5D%5E2)
substituting values
![n = [\frac{1.96 * 0.5 }{ 0.1} ]^2](https://tex.z-dn.net/?f=n%20%20%3D%20%20%5B%5Cfrac%7B1.96%20%2A%200.5%20%7D%7B%200.1%7D%20%5D%5E2)

The answer to the second question is no the validity is null this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the pH reading) from one rainfall will make the experiment invalid