5.7 × 10^7 km - 4.5 x 10^9 km

Answer 1

To subtract these numbers, we need to have the same exponent on the powers of 10. We can do this by expressing both numbers in scientific notation with the same exponent.

5.7 × 10^7 km can be written as 0.57 × 10^8 km, and

4.5 × 10^9 km can be written as 45 × 10^8 km.

Now we can subtract these two numbers:

0.57 × 10^8 km - 45 × 10^8 km = (0.57 - 45) × 10^8 km

= -44.43 × 10^8 km

So, 5.7 × 10^7 km - 4.5 × 10^9 km equals -44.43 × 10^8 km.