Answer:
The given sequence is geometric sequence
In the given pattern we have next number is 
Step-by-step explanation:
Given numbers are 64,-16,4,-1
To identify the pattern of the given numbers :
Let
,
,
and 
To find the next number that is 
common ratio 





Therefore the common ration is 
Therefore the given sequence is geometric sequence
The nth term of the geometric sequence is 
Now find the 5th term so put n=5 ,
we have





Therefore 
speed = distance / time = 100 m / 50 s = 2 m/sec
Juan average speed is 2 m / sec
The answer will be 141 adults
Let L represent the ladder length, and x the distance the horiz. ladder reaches out from the wall. Then L = x + 3, where x is the distance of the bottom of the ladder from the wall when the top of the ladder is 9 ft. above the ground.
Consider the triangle formed by the hypotenuse (L, same as ladder length), the (vertical) side opposite the angle formed by the hypo. (with length 9 ft) and the horiz side (which we will call x). Then, according to the Pythagorean Theorem,
L^2 = x^2 + 9^2. But L = x + 3, and L^2 = x^2 + 6x + 9 = x^2 + 9^2. Solving this equation results in x=3. 6x + 9 = 9^2, or
6x + 9 = 81
6x = 72
x = 12
But L = x+3. So L=12+3, or L = 15 (feet).