Exponential Equations Applications (solving with logarithms)

The half-life for plutonium-241 is 13 years. How long does it take for an initial 25 mg to decrease to 4 mg? Round to the nearest whole year.

t = _____ years

How many years will it take $3500 to triple if it is invested at 5.64% compounded continuously? Round to the nearest whole year.

t = _____ years

To solve 24000 = 12000e^0.03t , what would the next step be?

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• Dividing both sides by 0.03 

• Subtracting both sides by 0.03 
  

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• Divide both sides by 3

• Divide both sides by e

• Take the natural log of both sides

• Rewrite the exponent 0.08t as the coefficient of "e"

• Subtract e to both sides