The answer is A. If they buy 16 masks and 12 noses then that is 28.
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:
280
Step-by-step explanation:
first make a proportion. 7 over 250= x over 10,000. cross multiply to get 250x=70,000. 70,000 divided by 250 which gets you 280.
Answer:
45 green marbles
Step-by-step explanation: