35 and 36 on review

35:
The form for a geometric sequence is a_n=a_0*r^n.
Since a_2=18 and a_5=-2/3 we know that over three steps a_n has been multiplied by -1/27 we know that over one step it was multiplied by (–1/27)^(1/3)=-1/3.
So r=-1/3.
Here I take a short cut and turn a_2 into a_0. Then I have to turn a_100 into a_98.
18(-1/3)^98

36:
First, I set the parabola on a coordinate graph with the vertex at (0,16).
Then I wrote the equation in vertex form: y-16=a(x-0)^2
Then I inserted the x and y values of one of the points I had, (5,0), the right base of the arch: 0-16=5^2a.
Then I solved for a: a=-4/5
Then I inserted 3 for the x value in my equation: y=-4/5*3^2+16=44/5