Question 235 of 480
Simplify (√12−√3)(√12+√3)
- A. zero
- B. 1/3
- C. 3/5
- D. 1
Correct Answer:
B
Explanation
To simplify the expression
\[
\frac{(\sqrt{12} - \sqrt{3})}{(\sqrt{12} + \sqrt{3})}
\]
we will follow a systematic approach.
### Step 1: Simplify the Square Roots
First, let's simplify \(\sqrt{12}\):
\[
\sqrt{12} = \sqrt{4 \cdot 3} = \sqrt{4} \cdot \sqrt{3} = 2\sqrt{3}
\]
Now, we can substitute this back into our expression:
\[
\frac{(2\sqrt{3} - \sqrt{3})}{(2\sqrt{3} + \sqrt{3})}
\]
### Step 2: Combine Like Terms
Next, we simplify the numerator and the denominator:
**Numerator:**
\[
2\sqrt{3} - \sqrt{3} = (2 - 1)\sqrt{3} = \sqrt{3}
\]
**Denominator:**
\[
2\sqrt{3} + \sqrt{3} = (2 + 1)\sqrt{3} = 3\sqrt{3}
\]
Now, our expression looks like this:
\[
\frac{\sqrt{3}}{3\sqrt{3}}
\]
### Step 3: Simplify the Fraction
We can simplify this fraction by canceling \(\sqrt{3}\) in the numerator and denominator:
\[
\frac{\sqrt{3}}{3\sqrt{3}} = \frac{1}{3}
\]
### Final Answer
Thus, the simplified form of the original expression is:
\[
\frac{1}{3}
\]
### Explanation of Options
Now, let's analyze the options provided:
- **A. zero**: This is incorrect because we have a non-zero value of \(\frac{1}{3}\).
- **B. \(\frac{1}{3}\)**: This is the correct answer as we derived it through simplification.
- **C. \(\frac{3}{5}\)**: This is incorrect as it does not match our simplified result.
- **D. 1**: This is also incorrect because our result is \(\frac{1}{3}\), not 1.
### Common Pitfalls
1. **Not simplifying square roots**: Always simplify square roots where possible to make calculations easier.
2. **Forgetting to combine like terms**: Ensure you combine terms in the numerator and denominator before simplifying.
3. **Canceling incorrectly**: Only cancel terms that are identical in both the numerator and denominator.
### Revision Summary
- Simplify square roots before substituting them back into the expression.
- Combine like terms in both the numerator and denominator.
- Cancel common factors carefully to avoid mistakes.
- The final simplified answer for the expression \(\frac{(\sqrt{12} - \sqrt{3})}{(\sqrt{12} + \sqrt{3})}\) is \(\frac{1}{3}\).