Answer:
20ln(3)
Step-by-step explanation:
Put 15 for A and solve for t.
15 = 45e^(-.05t)
15/45 = 1/3 = e^(-.05t) . . . . divide by 45
ln(1/3) = -.05t . . . . . . . . . . . take natural logs
20ln(3) = t . . . . . . . . . . . . . . multiply by 20, simplify
It will take 20·ln(3) years for the area to decrease to 15 km^2.
Answer:
it is b
Step-by-step explanation:
Sameeeeeeeeeeeeeeeeeeeeeeee
We have that an inverse variation in a function is given by:

We must find the value of the constant k.
To do this, we substitute the values of x1 = 12, y1 = 15.
We have then:

Clearing k we have:

Substituting the value of k we have that the inverse variation is:

For y2 = 3 we have:

Clearing x2 we have:
Answer: