Questions: multiple choice question
Add or subtract the rational expression.
2/(g+10) + 2/(g^2-100)
A. 2g-18/((g+10)(g-10))
B. 2g+22/((g+10)(g-10))
C. 4/(g^2+g-90)
D. 4/((g+10)(g-10))
Transcript text: multiple choice question
Add or subtract the rational expression.
\[
\frac{2}{g+10}+\frac{2}{g^{2}-100}
\]
A.
\[
\frac{2 g-18}{(g+10)(g-10)}
\]
B.
\[
\frac{2 g+22}{(g+10)(g-10)}
\]
C.
$\frac{4}{g^{2}+g-90}$
D.
\[
\frac{4}{(g+10)(g-10)}
\]
Solution
Solution Steps
To add the rational expressions \(\frac{2}{g+10}\) and \(\frac{2}{g^{2}-100}\), we first need to find a common denominator. Notice that \(g^2 - 100\) can be factored as \((g+10)(g-10)\). Thus, the common denominator for the two fractions is \((g+10)(g-10)\). We then rewrite each fraction with this common denominator and add them together.
Step 1: Identify the Common Denominator
To add the rational expressions \(\frac{2}{g+10}\) and \(\frac{2}{g^{2}-100}\), we first recognize that \(g^2 - 100\) can be factored as \((g+10)(g-10)\). Therefore, the common denominator for both fractions is \((g+10)(g-10)\).
Step 2: Rewrite Each Expression
We rewrite each fraction with the common denominator:
\[
\frac{2}{g+10} = \frac{2(g-10)}{(g+10)(g-10)}
\]
\[
\frac{2}{g^{2}-100} = \frac{2}{(g+10)(g-10)}
\]
Step 3: Add the Expressions
Now we can add the two fractions:
\[
\frac{2(g-10)}{(g+10)(g-10)} + \frac{2}{(g+10)(g-10)} = \frac{2(g-10) + 2}{(g+10)(g-10)}
\]
Step 4: Simplify the Result
Combining the numerators gives:
\[
2(g-10) + 2 = 2g - 20 + 2 = 2g - 18
\]
Thus, the combined expression simplifies to:
\[
\frac{2g - 18}{(g+10)(g-10)}
\]
Final Answer
The final simplified expression is \(\boxed{\frac{2g - 18}{(g+10)(g-10)}}\).