Calculus II: How do I write the form of partial fraction decomposition?

[BlueKai]

For this function:

7x-5/x(x²+4)²

I attempted it and came up with:

A/X + B/x²+4 + Cx+D/(x²+4)<sup>2

I took a referenced an example closest to this problem from within my book. But my online MathLab marks it wrong.</sup>

 

[Deleted member 4993]

For this function:

(7x-5)/x(x²+4)²

I attempted it and came up with:

A/X + B/x²+4 +(Cx+D)/(x²+4)<sup>2

I took a referenced an example closest to this problem from within my book. But my online MathLab marks it wrong.</sup>

Did you put those parentheses()?

Those are very important.

 

[BlueKai]

Did you put those parentheses()?

Those are very important.

That didn't work

 

[lookagain]

For this function:

(7x - 5)/[x(x² + 4)²]


I attempted it and came up with:

A/x + B/(x² + 4) + (Cx + D)/(x² + 4)<sup>2



I took a referenced an example closest to this problem from within my book. But my online MathLab marks it wrong.</sup>

The above now shows all needed grouping symbols *if* that were the correct set-up.

However, it is *not* a correct set-up.



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You need this set-up:


\(\displaystyle \dfrac{A}{x} \ + \ \dfrac{Bx + C}{x^2 + 4} \ + \ \dfrac{Dx + E}{(x^2 + 4)^2} \ = \ \dfrac{7x - 5}{x(x^2 + 4)^2}\)

 

[BlueKai]

Solved

The above now shows all needed grouping symbols *if* that were the correct set-up.

However, it is *not* a correct set-up.



- -- - - -- - - - - - - - - -- - - - - - - - -- - -- - - - - - - - -- - -- - - - - -- - - - - - -- - - - - - - - - -- - -


You need this set-up:


\(\displaystyle \dfrac{A}{x} \ + \ \dfrac{Bx + C}{x^2 + 4} \ + \ \dfrac{Dx + E}{(x^2 + 4)^2} \ = \ \dfrac{7x - 5}{x(x^2 + 4)^2}\)

So that's what it was! Thanks a bunch:-o