Answer: 
Step-by-step explanation:
We know that the general form of the exponential decay formula is
, where y is final amount remaining after t time, A is the original amount and r is the rate of decay
Now, the ratio of strontium-90 remaining, p , as a function of years, t , since the nuclear accident. 
Hence, the ratio of remaining since the nuclear accident is 
Answer:
for q 19 its x=209ft and for 21 its 66.5 ft i forgot q 20
Step-by-step explanation:
1st way- 3^2 * 3^3
2nd way- 3 * 3^4
3rd way- 3^0 * 3^5
<h2>Solution (a) :-</h2>
Let the cost of the less expensive comic book be x .
Then :-

Using this equation , we can find the cost of the less expensive comic book .
Price of the less expensive book :-





Cost of the less expensive book is 107 .
Therefore , the epice of the less expensive book = $ 107 .
<h2>Solution (b) :-</h2>
Cost of the more expensive book = 11x
Which means :-






Therefore , the price of the more expensive book = $ 1177 .
Answer:
wrong it is b*h/2
Step-by-step explanation: