Answer:
Second option: 5E 10 = 5*10^(10) galaxies.
Step-by-step explanation:
The exponential notation is used as:
AE N
This is equal to:
A*10^(N)
And we need to add N zeros to the right of A.
While if we had:
AE - N
A*10^(-N)
We need to add N - 1 zeros at the left of A.
Now we have the number:
50,000,000,000
Let's count the number of zeros at the right of the 5, we have 10 zeros.
Then we would write this as:
5*10^(10)
OR
5E 10
Then the correct option is the second one.
