When you are checking your answers, your formula should read out as 9(2.222) - 8 = 12, which is simply filing in the x value that you calculated (it comes out to 11.998 which is correct). You wrote it out as 9(2.22) - 8 = -6, which is why your checking process was incorrect
Answer:
Imagine an easier version of this problem: You have a board 5 feet long that you must cut (divide, right?) into two equal parts. It is probably clear to you that you simply divide the length (5) by the number of parts you're dividing it into (2) to obtain the length of each piece (2.5 feet).
Use the same method for your problem 5 feet divided by 6 is 0.83 feet per piece.
We do not ordinarily divide feet into decimal portions, but instead into inches. Since an inch is 1/12 of a foot, you could simply say 5/6 = how many twelfths? or 5/6 = n/12 Solve this by inspection or by cross multiplying 5 times 12 equals n times 6. So n must equal 10, and your pieces of board are each 10 inches long.
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:
Answer:
<h2>D</h2>
Step by step explanation:
<h2>Just took the quiz.</h2>
You need to set the correct porportion. x is the percent value you want to find. 100 is the maximum percentage. 420mg is what was taken out of the maximum 560mg dose.

You will cross multiple.

you will divide 42000 by 560


The complete answer will be: The patient took 75% of the 560mg dose of medication.