Answer:
2x^3+2x-1
Step-by-step explanation:
 
        
             
        
        
            
            
                What is the solution set of x2 + y2 = 26 and x − y = 6? A. {(5, -1), (-5, 1)} B. {(1, 5), (5, 1)} C. {(-1, 5), (1, -5)} D. {(5,  
                Rus_ich [418]             
         
        
He two equations given are
x^2 + y^2 = 26
And
x - y = 6
x = y +6
Putting the value of x from the second equation to the first equation, we get
x^2 + y^2 = 26
(y + 6) ^2 + y^2 = 26
y^2 + 12y + 36 + y^2 = 26
2y^2 + 12y + 36 - 26 = 0
2y^2 + 12y + 10 = 0
y^2 + 6y + 5 = 0
y^2 + y + 5y + 5 = 0
y(y + 1) + 5 ( y + 1) = 0
(y + 1)(y + 5) = 0
Then 
y + 1 = 0
y = -1
so x - y = 6
     x + 1 = 6
x = 5
Or
y + 5 = 0
y = - 5
Again x = 1
So the solutions would be (-1, 5), (1 , -5). The correct option is option "C".
        
                    
             
        
        
        
Answer:
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
Step-by-step explanation:
Confidence interval:
Sample mean plus/minus the margin of error.
In this question:
Mean of 23.
Margin of error 2.1.
Then
23 - 2.1 = 20.9
23 + 2.1 = 25.1
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
 
        
             
        
        
        
Answer:
40/100 = .4 = 40%
Step-by-step explanation:
 
        
                    
             
        
        
        
One interpretation of your intent would be as follows:
                  16x^11y^8
Find 4 √ [-----------------]. Is that what you meant?
                    81x^7y^6
                                                                 4*x^5*√x*y^4
If so, then the correct result would be 4 --------------------- 
                                                                   9*x^3*√x*y^3
and this could be reduced to:
        4*x^5 * y^4 * √(x)     4*x^2*y 
4 --------------------------- = -------------
       9*x^3*y^3 √(x)               9