## voe HELP!!! I have no idea for this question! 5. The half-life of a certain radioactive material is 78 hours. An initial amount of the material has a mass of 790 kg. Write an exponential function that models the decay of this material. Find how much radioactive material remains after 18 hours. Round your answer to the nearest thousandth. (1 point) one year ago one year ago

1. Algebraic!

have you learned about e^x ?

2. Algebraic!

or are you using (1/2)^x ...?

3. Algebraic!

$\huge A(t) = A _{0}*(\frac{ 1 }{ 2})^{\frac{ t }{ t _{halflife} }}$

4. Algebraic!

Ao is the initial amount of the substance t halflife is the halflife of the substance

5. voe

so would the answer be y= 790 (1/2)^1/78 ; 673.233kg ?? or is that wrong

6. Algebraic!

you meant to type: y= 790 (1/2)^18/78 ...I think. Yes that's right.

7. voe

ok thanks!!