The answer is 9.276 * 10^7 miles
I'm using the asterisk symbol * instead of the x symbol to mean "multiply"
===================================================================
Step-by-step explanation:
They want you to find the difference in those distances. This means you'll subtract the values (large minus small). Before you can subtract, you need to make sure that both exponents over the 10 are the same; otherwise, subtraction won't make much sense and you'll most likely get a bad answer. Thankfully we can do a conversion.
Start with the larger exponent 10^7. Note how we can break it up like this:
10^7 = 10^(2+5) = 10^2*10^5 = 100*10^5
I used the rule a^(b+c) = a^b*a^c and then I simplified the value of 10^2 to be 100
The key is that we have a 10^5 in there.
So we can write 9.3 * 10^7 like so:
9.3 * 10^7 = 9.3 * 100*10^5
9.3 * 10^7 = (9.3 * 100)*10^5
9.3 * 10^7 = 930 * 10^5
The exponent portion 10^5 matches up with the other number's exponent portion
-----------------------------------------------------------------
So we want to find the difference between the distances 2.4*10^5 and 930*10^5
Subtract the distances
(Larger) - (Smaller) = (930*10^5) - (2.4*10^5) = (930-2.4)*10^5 = 927.6*10^5
The exponent part 10^5 stays the same. The bases 930 and 2.4 subtract like any other pair of numbers.
The last step is to convert to scientific notation
927.6*10^5 = (927.6)*10^5
927.6*10^5 = (9.276*10^2)*10^5
927.6*10^5 = 9.276*(10^2*10^5)
927.6*10^5 = 9.276*10^(2+5)
927.6*10^5 = 9.276*10^7
which is the final answer.
I would avoid rounding the 9.276 to 9.3 because it would cause a bit of confusion. It would make the difference seem exactly the same as the distance from earth to the sun, but that's not the case here.