I will do the first-two lines only.
-4 -3 -2 -1 0 1 2 3 4 5 6
Next line below.
-5 -4 -3 -2 -1 0 1 2 3 4 5
Do the rest.
Answer:
Even if a person doesn't show symptoms, they can still have it.
Step-by-step explanation:
That's the problem.
Even if you think everyone isn't sick, they very well could be, and because there is no vaccine and it spreads so quickly, there's a chance that all the people in that group could get it.
Answer:
Na20+H20 -> 2NaOH
Step-by-step explanation:
Don't let fractions fool you.

of a tank in

an hour is equal to:
1/12 of a tank in 20 minutes.
Thus we know in an hour, an oil company can fill 3/12 of a tank (60 minutes in an hour).
3 x 4 = 12, and 12/12 = 1(a whole tank), so we multiply 1 (hour) by 4.
Our answer is that it takes 4 hours to fill a tank.
I don't know what method is referred to in "section 4.3", but I'll suppose it's reduction of order and use that to find the exact solution. Take

, so that

and we're left with the ODE linear in

:

Now suppose

has a power series expansion



Then the ODE can be written as


![\displaystyle\sum_{n\ge2}\bigg[n(n-1)a_n-(n-1)a_{n-1}\bigg]x^{n-2}=0](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Csum_%7Bn%5Cge2%7D%5Cbigg%5Bn%28n-1%29a_n-%28n-1%29a_%7Bn-1%7D%5Cbigg%5Dx%5E%7Bn-2%7D%3D0)
All the coefficients of the series vanish, and setting

in the power series forms for

and

tell us that

and

, so we get the recurrence

We can solve explicitly for

quite easily:

and so on. Continuing in this way we end up with

so that the solution to the ODE is

We also require the solution to satisfy

, which we can do easily by adding and subtracting a constant as needed: