Answer:

The vertex form for a parabola is given by this expression:

By direct comparison we see that for this case:

And we know from the general expression that the vertex is:

So then the vertex for this case is:

Step-by-step explanation:
For this case we have the following function:

And we need to take in count that the vertex form for a parabola is given by this expression:

By direct comparison we see that for this case:

And we know from the general expression that the vertex is:

So then the vertex for this case is:

 
        
             
        
        
        

1) Since in the USA 8 x 10 ^9 messages are sent every month, that means that approximately 8 billion messages are sent.
2) We can Prime factorize it:
Note that on the right side we've picked only prime numbers. In this case, 2 and 5.
So we can rewrite 8 x 10^9 as prime factors.

3) Hence, the answer is:
 
 
        
             
        
        
        
Find his rate:
120 / 15 = $8 per hour
Multiply the rate by hours:
$8 x 20 hours = $160
He will earn $160
        
             
        
        
        
Let's put it this way. 
It's a ratio of 6:72 and we need to change it in a way to find number of rooms cleaned in 9 days.
Divide 6 & 72 both by 2
Ratio is now 3:36
Multiply 3 & 36 both by 3
Ratio is now 9:108
The number of rooms in which Robin can clean in 9 days is 108 rooms. 
        
                    
             
        
        
        
Answer:
Answer should be D and E
Step-by-step explanation:
First, you need to figure out the radius of B. 
As radius of A is 6 in, 20% of 6in would be 1.2in. So total radius of B = 6+1.2 = 7.2
Now you get the radius of B, calculate th area of B using the formula πr^2.
= π(7.2)^2 = 162.86 = area of B
Now, all answers except D and E is smaller than B. So, the answer would be D and E.