**Answer:**

for 12 people cut everything in half

for 36 add the 12 to 24 people

**Answer:**

A)

B)

C) τ=2326 years

**Step-by-step explanation:**

A)

Consider the differential equation:

Separate variables dD and dt:

Integrate: Remember that The integral of dD/D is ln(D).

And do , so:

B)

The function we have found is a function that let us know how many of Ra is after t years, so, evaluate the function at t=100:

**Which rounded is 95.8.**

C) For this equation it is known that the life half life τ is equal to (1/λ), where λ is the exponential number that is multiplying to **-**t in the D(t) function; so for this case, λ=0.00043, and the life half life is ,

which rounded is equal to 2326 years.

**Answer:**

-18

**Step-by-step explanation:**

-8 + 70/-7

-8 - 10

-18

Formula for degree to radian:

degree ×

so...

Exact answer:

Rounded answer:

4.89

Hope this helped!