2. Which of the following relations is/are function/s?

Hello!

(x+a)·(x+b) equals x²+xa+xb+ab which simplifies to x²-12x-45

x² equals x²
xa+xb can be expressed as (a+b)x = -12x thus, (a+b) = -12
ab equals -45

Under what conditions do (a+b) equal -12 and ab equal -45?

+3-15 results in -12 while (+3)(-15) gives -45
-3-15 yields -18 and (-3)(-15) results in +45
+3+15 produces +18 and (+3)(+15) also equal to +45
-3+15 equals +12 and (-3+15) results in -45

Conclusion:

(x+3)(x-15) 

Answer:

The number of standard deviations above the mean is

Step-by-step explanation:

The question indicates that:

   The average weight of the corn ears from each farm is

   The standard deviation for the corn ears from Iowa is

   The standard deviation for the corn ears from Ohio is

     

     

  A randomly chosen ear of corn from Iowa weighs  x =  1.39 pounds

  The standardized score is  z = 1.645

  The weight of a randomly chosen ear of corn from Ohio measures  

In general, the standardized score of corn weight from Iowa can be mathematically defined as:

       

=>      

=>        

=>        

Conversely, the standardized score of corn weight from Ohio is expressed as:

         

=>      

=>        

=>      

A positive value indicates this quantity represents the number of standard deviations above the mean.