If  is the amount of strontium-90 present in the area in year
 is the amount of strontium-90 present in the area in year  , and it decays at a rate of 2.5% per year, then
, and it decays at a rate of 2.5% per year, then

Let  be the starting amount immediately after the nuclear reactor explodes. Then
 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
 is measured in years. We're told that 2.5% of the starting amount  decays after 1 year, so that
 decays after 1 year, so that

Then after 50 years, we have

 
        
             
        
        
        
Answer:
Once both the House and Senate have approved the bill in identical form, it becomes "Enrolled" and sent to the President of the United States. The President may sign the bill into law. The President can also take no action on the bill for ten days while Congress is in session and the bill will automatically become law.
 
        
             
        
        
        
Its a multiplication by -3 on each term, so I think you're gonna answer is by r=-3, maybe?
        
             
        
        
        
Answer:
Your answer would be D: isometry
Step-by-step explanation: