Answer:
The vertices are (-16,-5) and (14,-5)
The foci are (-26,-5) and (24,-5)
17,190 / 5,730 = 3. This means we must divide 70mg in half 3 times
70 / 2 = 35
35 / 2 = 17.5
17.5 / 2 = 8.75
There will be 8.75 mg left after 17,190 years.
So, notice, the focus point is at -7, 5, and the directrix is at y = -11.
keep in mind that the vertex is half-way between those two fellows, and the distance from the vertex to either one of them is "p" units, check the picture below.
with that focus point and that directrix, the half-way over the axis of symmetry will be -7, -3, that's where the vertex is at, and notice the distance "p", is 8 units.
since the parabola is opening upwards, "p" is positive 8.
The rate of change of the equation x=9 is 9.