Answer: 
Step-by-step explanation:
The area of a rectangle can be calculated with this formula:

Where "l" is the lenght and "w" is the width.
You know that the dimensions of this rectangle are 5*10⁵meters and 4*10⁴ meters, then you need to multiply them to get the area:

Since 10⁵ and 10⁴ have equal base, you must add the exponents:


Scientific notation has the form:

Where "a" is any number between 1 and 10 but less than 10, and "n" is an integer.
Since 20 is greater than 10, you must move the decimal point to the left:

Rewriting the result, you get:
