<h2>
Answer:</h2>

or
4 to the 21st over 5 to the 6th.
<h2>
Step-by-step explanation:</h2>
First, we need to write our expression. Let's do it step by step:
<u>4 to the 7th:</u>

<u>5 squared:</u>

<u>4 to the 7th over 5 squared:</u>

<u>4 to the 7th over 5 squared all raised to the 3rd power:</u>
<u>
</u>
Using the law of exponents:

Finally, the answer is 4 to the 21st over 5 to the 6th.
Answer: D
Step-by-step explanation:A scientist who studies the objects in the sky, including planets, galaxies, black holes, and stars, is called an astronomer
Answer: 
Step-by-step explanation:
Given
Max is driving at a speed of 
It took him three-quarters of a second i.e. 
Speed in meter per second is 
Distance is given by

Reaction distance is

I got the answer 18.79
I believe this is correct, Please tell me if im wrong. :)
Answer:
2:9
Step-by-step explanation
4:18 divided by 2 is the lowest it can go so 4 divided by 2 is 2
18 divided by 2 is 9 so,
2:9