1.727*10^6km2-3140km^2

1.72386*10^6 km^2

Step-by-step explanation:

When I do math with scientific notation I change both to have the same exponent, then you can just do normal arithmetic. This also includes getting rid of the exponent, which I do here.

1.727*10^6 - 3140

Let's go ahead and get rid of the scientific notation for the first one. So 1.727*10^6 = 1,727,000

So now we have 1,727,000 - 3140 = 1,723,860

Since we started in scientific notation let's go back to it. 1.72386*10^6