Answer:
6,400 km = 6.4 x 10³ km.
Step-by-step explanation:
Measurements => Scientific Notation.
Scientific notation is a way to express numbers as the product of two numbers: a coefficient and the number 10 raised to a power. The exponent must be a non-zero integer, it can be either positive or negative. The value of the coefficient is greater than or equal to 1 but it should be less than 10.
In this case, we request to write 6,400 kilometers in scientific notation. Based on the concept of scientific notation, our coefficient would be 6.4 because is greater than 1 and less than 10. 6,400 is a positive integer that contains 4 digits, so we have to multiply 6.4 by 1000 to obtain 6,400. 1000 equals 10³, so the 6,400 kilometers in scientific notation would be 6.4 x 10³ kiloem km.