Answer:
answer is b
Step-by-step explanation:
Option A: 
Option E: 
Option F: 
Solution:
Given expression is
.
To find which expression is equivalent to the given expression.
Option A: 
Using exponent rule: 

Therefore
is equivalent to the given expression.
Option B: 
It is not equivalent to the given expression.
Option C: 

Therefore, It is not equivalent to the given expression.
Option D: 

Therefore, It is not equivalent to the given expression.
Option E: 

Therefore, It is equivalent to the given expression.
Option F: 

Therefore, It is equivalent to the given expression.
Hence option A, Option E and Option E are equivalent to the given expression.
Using a trigonometric equation, it is found that it will take 2.28 minutes until the two trains are first equidistant from the child.
<h3>What is the distance of each train to the child?</h3>
The distance of the first train is:

The distance of the second train is:

<h3>When are the trains equidistant to the child?</h3>
When
, hence:

The following substitution is made:

Hence:


Which is a quadratic equation with coefficients
, hence:



Then, applying the trigonometric equation, considering that
due to the range of the cosine function:


It will take 2.28 minutes until the two trains are first equidistant from the child.
You can learn more about trigonometric equations at brainly.com/question/2088730
The general equation for height is:
h = -0.5gt^2 + (v0)t + h0, where g = -9.8 m/s^2 or -32 ft/s^2, v0 = initial velocity, and h0 = initial height.
1) h = -4.9t^2 + 19: -4.9 means the units are in meters, and 19 means that the initial height was 19 m, which is group C.
2) -16t^2 means the units are in feet, and 50t means that the initial velocity was 50 ft/s upwards. This is group B.
3) -16t^2 again means the units are in feet, and 50 means the initial height was 50 ft. This is group D.
4) -4.9t^2 means the units are in meters, and 19 is the initial height of 19 m. This is for group A.
96/24 = 4
25*4=6x+28
72=6x
x=12