By letting

we get derivatives


a) Substitute these into the differential equation. After a lot of simplification, the equation reduces to

Examine the lowest degree term
, which gives rise to the indicial equation,

with roots at r = 0 and r = 4/5.
b) The recurrence for the coefficients
is

so that with r = 4/5, the coefficients are governed by

c) Starting with
, we find


so that the first three terms of the solution are

Answer:
1 , 3 , 13 , and 39
Step-by-step explanation:
1 x 39 =39
3 x 13 = 39
13 x 3 = 39
39 x 1 =39
Given:
y-intercept of the graph: (0, 90)
zeros: 5 and 9
The equation that models the function based on the zeros given, is either
y = 90 (x-5) (x-9)
or
y= 2(x-5)(x-9)
try solving for the y-intercept of each function,
y = 90 (0-5) (0-9)
y = 4050
(0, 4050)
y = 2(0-5) (0-9)
y = 90
(0, 90)
therefore, the equation that models the function is y = 2(x-5)(x-9)
I believe it 16/225 in fraction form