Answer:
54
Step-by-step explanation:
64 + 62 = 126
180 - 126 = 54
The formula for half-life is:
![A = P(0.5)^{t/h}](https://tex.z-dn.net/?f=A%20%3D%20P%280.5%29%5E%7Bt%2Fh%7D)
A is the amount remaining, P is the initial amount, t is the time that has passed, and h is the half-life of the substance. Plug in the values that you know and solve:
![4 = P(0.5)^{35/20} \\ \\ 4 = P(0.5)^{1.75} \\ \\ P = \frac{4}{0.5^{1.75}} \\ \\ P \approx 13.4543426441](https://tex.z-dn.net/?f=4%20%3D%20P%280.5%29%5E%7B35%2F20%7D%20%5C%5C%20%5C%5C%204%20%3D%20P%280.5%29%5E%7B1.75%7D%20%5C%5C%20%5C%5C%20P%20%3D%20%5Cfrac%7B4%7D%7B0.5%5E%7B1.75%7D%7D%20%5C%5C%20%5C%5C%20P%20%5Capprox%2013.4543426441)
Rounded to the nearest whole number, the density of the substance was about 13<span>mg / cm².</span>
Answer:
No
Step-by-step explanation:
I don't think it is proportional