The value of $\frac{(a + b)^2}{(a^2 - b^2)}$ is
Aptitude
Simplification
Difficulty: Easy
Choose an option
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A$\frac{ab}{a + b}$
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B$\frac{2ab}{a - b}$
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C$\frac{a + b}{a - b}$
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DNone of these
Answer
Correct Answer: $\frac{a + b}{a - b}$
Explanation
### Concept & Formula
This is a fundamental algebraic simplification problem based on factoring the **Difference of Squares**.
$$A^2 - B^2 = (A - B)(A + B)$$
### Step-by-Step Solution
Given expression:
$\frac{(a + b)^2}{a^2 - b^2}$
**Step 1: Expand and Factor**
Rewrite the numerator by expanding the square into its two identical binomial factors:
$(a + b)^2 = (a + b)(a + b)$
Apply the difference of squares identity to factor the denominator:
$a^2 - b^2 = (a - b)(a + b)$
**Step 2: Substitute and Cancel**
Place the expanded forms back into the fraction:
$= \frac{(a + b)(a + b)}{(a - b)(a + b)}$
You can see that the binomial $(a + b)$ exists in both the numerator and the denominator. Cancel out one instance of $(a + b)$ from the top and the bottom (assuming $a + b \neq 0$):
$= \frac{a + b}{a - b}$
### Exam Strategy & Shortcut
**Direct Recognition:** This is a basic identity relationship. You should ideally recognize instantly that $a^2 - b^2$ contains one $(a + b)$ factor which will cancel one of the $(a + b)$ factors on top, leaving exactly one $(a + b)$ on top and the $(a - b)$ on the bottom. This should take less than 3 seconds to answer without any calculation.
### Common Pitfall
A common error among beginners is mistakenly expanding the numerator as $a^2 + b^2$, and then being unable to cancel anything with the denominator. Remember that $(a + b)^2 \neq a^2 + b^2$.
### Final Answer
Therefore, the correct answer is **$\frac{a + b}{a - b}$**.