Answer:

Step-by-step explanation:
The comma is important here, otherwise "one third of a number n minus 7" is

Answer:
(1). 15
Step-by-step explanation:
The time it takes to travel the whole path will be 20 times the time it takes to travel 1/20 of the path.
20 × (3/4) s = 60/4 s = 15 s
It will take 15 seconds to travel the entire path.
Answer:
{0}
Step-by-step explanation:
{0} is not because 0 is not an element of set {1, 2, 3}
The null set is a subset of every set, so Ø is.
A set is a subset of itself.
Answer:
1/9 cup of sugar for every 1/4 cup of flour
Step-by-step explanation: Turn the 1/3 into 3/9 and I'm sure you can figure it out from there.



Substituting into the ODE

gives

so that the coefficients of the series are given according to

We can shift the index in the recursive part of this definition to get

for
. There's dependency between coefficients that are 2 indices apart, so we can consider 2 cases:
- If
, where
is an integer, then

but since
, we have
and
for all
.
- If
, then



and so
for all
. If
, we then have
and
.
So the ODE has solution
