To find when the ball reaches the ground, you would need to find the time that gives you a height value of zero. 
Your answer would be 4 seconds
h = -16(4)^2 + 64(16)
h = -16(16) + 256
h = -256 + 256
h = 0
Hope this helps!
        
                    
             
        
        
        
b
こんにちは
mmmmmmmmnnnnnnnnnnnnnnnnnnnnnnn
 
        
             
        
        
        
A. =4^(-11/3)*4^(2/3)
 =4^(-9/3)
 =4^(-3)
 =1/64
        
             
        
        
        
Answer:
c
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
Part a) Option d 
Part b) Option a
Step-by-step explanation:
Part a
if we look at the options given and the data available
Option a) x^4+9 
Putting x= 2 we get (2^4) + 9 =25
Putting x= 3 we get (3^4) + 9 =90 but f(x) =125 so not correct option
Option b) (4^x)+9 
Putting x= 2 we get (4^2) + 9 =25
Putting x= 3 we get (4^3) + 9 =73 but f(x) =125 so not correct option
Option c) x^5
Putting x= 2 we get (2^5)  =32 but f(x) =25 so not correct option
Option d) 5^x
Putting x= 2 we get (5^2)  =25
Putting x= 3 we get (5^3)  =125
Putting x= 4 we get (5^4)  =625
So Option d is correct.
Part (b)
3(2)^3x
can be solved as:
=3(2^3)^x
=3(8)^x
So, correct option is a