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Show your worksimplify the sum. State any restrictions on the variables.(x-2)/(x+3) + 10x/(x^2-9)

User LOLapalooza
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1 Answer

16 votes
16 votes

Answer:

(x + 2)/(x - 3) when x is different to 3 and -3.

Step-by-step explanation:

The initial expression is


(x-2)/(x+3)+(10x)/(x^2-9)

Since (x² - 9) = (x + 3)(x - 3), we get:


(x-2)/(x+3)+(10x)/((x+3)(x-3))

Then, the denominator can't be zero, so x should be different to 3 and to -3. Because

x + 3 = 0 --> x = -3

or

x - 3 = 0 --> x = 3

Then, we can add the fractions as follows


\begin{gathered} ((x-2)(x-3))/((x+3)(x-3))+(10x)/((x+3)(x-3)) \\ \frac{(x-2)(x-3)+10x_{}}{(x+3)(x-3)} \end{gathered}

Simplifying, we get


\begin{gathered} ((x^2-5x+6)+10x)/((x+3)(x-3)) \\ =(x^2+5x+6)/((x+3)(x-3)) \\ =\frac{(x+2)(x+3)_{}}{(x+3)(x-3_{})}=((x+2))/((x-3)) \end{gathered}

Therefore, the sum is equal to (x + 2)/(x - 3) when x is different to 3 and -3.

User John Pankowicz
by
2.8k points
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