Answer: 125 miles
if you do the math you will get the same answer.
Wouldn't it be divided, I'm pretty sure it would be, if not I'm sorry
When you are multiplying exponents with the same base, you can add the exponents. This is represented as:

In our case we are multiplying exponents with the same base 8 and exponents -7 and 5. The sum of -7 and 5 is -2, so our answer is
.
I believe it would be 6(10^4)
If
is the amount of strontium-90 present in the area in year
, and it decays at a rate of 2.5% per year, then

Let
be the starting amount immediately after the nuclear reactor explodes. Then

or simply

So that after 50 years, the amount of strontium-90 that remains is approximately

or about 28% of the original amount.
We can confirm this another way; recall the exponential decay formula,

where
is measured in years. We're told that 2.5% of the starting amount
decays after 1 year, so that

Then after 50 years, we have
