Answer:
d) ≤
Step-by-step explanation:
 
        
                    
             
        
        
        
N.b., this is copied from an answer I wrote for someone else.Thinking about the graph of y, the rate of change is zero whenever there is an extremum.
First, differentiate y.

Next, find the zeros of y' by factoring.

Now, we substitute these x-values into the 
original equation to find the coordinates. 
 
 
        
             
        
        
        
Answer:
 
  
Step-by-step explanation:
information given
 represent the sample mean
 represent the sample mean  
 represent the population standard deviation
 represent the population standard deviation 
 sample size
 sample size  
 represent the value that we want to test
 represent the value that we want to test  
 represent the significance level for the hypothesis test.
 represent the significance level for the hypothesis test.  
z would represent the statistic 
 represent the p value for the test
 represent the p value for the test 
Hypothesis to test
We want to test if the true mean is less than 12, the system of hypothesis would be:  
Null hypothesis: 
  
Alternative hypothesis: 
  
The statistic is given by:
 (1)
 (1)  
Replacing the info given we got:
We can replace in formula (1) the info given like this:  
 
  
 
        
             
        
        
        
Answer:
1. Her time in minutes is 720/s minutes
2. Given her time to be 20 minutes, her speed is 36 mph 
Step-by-step explanation:
Mathematically, 
Distance = speed * time 
In this question, we want to calculate time;
So time = distance/speed 
times = 12 miles/s mph = 12/s hours 
Now we want our answer in minutes 
Kindly recall that 60 minutes = 1 hour 
So 12/s hours will be 12/s * 60 = 720/s minutes 
2. Since she drives from home to the office in in 20 minutes, we want to calculate her speed in mph 
From the time calculated above i.e 720/s 
We can equate 20 = 720/s 
20s = 720 
s = 720/20
s = 36 mph 
 
        
                    
             
        
        
        
Answer:
B
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180° , then
y + 10 + 2y + 50 = 180 , that is
3y + 60 = 180 ( subtract 60 from both sides )
3y = 120 ( divide both sides by 3 )
y = 40 → B