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What is the sum of22 - 4... and 2?+7 + 22+1-291

User Siddharth Nayar
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1 Answer

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15 votes

We are asked to find the sum of the following terms


(7x)/(x^2-4)\; and\; (2)/(x+2)

Let us find their sum.

First of all, notice that the following denominator can be factored as


x^2-4=x^2-2^2=(x-2)(x+2)

So, the expression becomes


\begin{gathered} (7x)/((x-2)(x+2))+(2)/(x+2) \\ \end{gathered}

Add them by taking the LCM


(7x)/((x-2)(x+2))+(2)/(x+2)=(7x+(x-2)\cdot2)/((x-2)(x+2))

Simplify the expression


(7x+(x-2)\cdot2)/((x-2)(x+2))=(7x+2x-4)/((x-2)(x+2))=(9x-4)/((x-2)(x+2))

Finally, re-write the denominator in the expanded form as it was written before.


(9x-4)/((x-2)(x+2))=(9x-4)/(x^2-4)

Therefore, the simplified expression is


(9x-4)/(x^2-4)

User Vasily Kabunov
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