A.12 because i had same question
 
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Answer:
B. -0.5
Step-by-step explanation:
I calculated it logically
 
        
             
        
        
        
We have been given that a huge ice glacier in the Himalayas initially covered an area of 45 square kilo-meters. The relationship between A, the area of the glacier in square kilo-meters, and t, the number of years the glacier has been melting, is modeled by the equation  .
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To find the time it will take for the area of the glacier to decrease to 15 square kilo-meters, we will equate  and solve for t as:
 and solve for t as:



Now we will switch sides:

Let us take natural log on both sides of equation.

Using natural log property  , we will get:
, we will get:










Therefore, it will take  years for area of the glacier to decrease to 15 square kilo-meters.
 years for area of the glacier to decrease to 15 square kilo-meters.
 
        
             
        
        
        
Answer:
1/2 ^w : decay factor after w weeks
hope this helps
Step-by-step explanation: