Question 164 of 480
Simplify (√98 -√50)/√32
Correct Answer:
C
Explanation
To simplify the expression \((\sqrt{98} - \sqrt{50})/\sqrt{32}\), we will break it down step by step.
### Step 1: Simplify the square roots in the numerator
1. **Simplifying \(\sqrt{98}\)**:
- We can factor \(98\) into \(49 \times 2\).
- Since \(49\) is a perfect square, we can simplify:
\[
\sqrt{98} = \sqrt{49 \times 2} = \sqrt{49} \times \sqrt{2} = 7\sqrt{2}
\]
2. **Simplifying \(\sqrt{50}\)**:
- We can factor \(50\) into \(25 \times 2\).
- Since \(25\) is a perfect square, we can simplify:
\[
\sqrt{50} = \sqrt{25 \times 2} = \sqrt{25} \times \sqrt{2} = 5\sqrt{2}
\]
### Step 2: Substitute back into the expression
Now we can substitute the simplified square roots back into the original expression:
\[
\frac{\sqrt{98} - \sqrt{50}}{\sqrt{32}} = \frac{7\sqrt{2} - 5\sqrt{2}}{\sqrt{32}}
\]
### Step 3: Combine the terms in the numerator
In the numerator, we can combine like terms:
\[
7\sqrt{2} - 5\sqrt{2} = (7 - 5)\sqrt{2} = 2\sqrt{2}
\]
### Step 4: Simplify the denominator
Next, we simplify \(\sqrt{32}\):
- We can factor \(32\) into \(16 \times 2\).
- Since \(16\) is a perfect square, we can simplify:
\[
\sqrt{32} = \sqrt{16 \times 2} = \sqrt{16} \times \sqrt{2} = 4\sqrt{2}
\]
### Step 5: Substitute back into the expression
Now we substitute the simplified denominator back into the expression:
\[
\frac{2\sqrt{2}}{4\sqrt{2}}
\]
### Step 6: Cancel out the common terms
We can cancel \(\sqrt{2}\) from the numerator and the denominator:
\[
\frac{2}{4} = \frac{1}{2}
\]
### Final Answer
Thus, the simplified expression is:
\[
\frac{1}{2}
\]
### Explanation of Options
- **Option A: 3** - This option is incorrect because the simplification does not yield a whole number; the calculations show that the result is a fraction.
- **Option B: 1** - This option is incorrect as the simplification results in \(\frac{1}{2}\), not \(1\).
- **Option C: \(\frac{1}{2}\)** - This is the correct answer as shown in the detailed steps above.
- **Option D: \(\frac{1}{4}\)** - This option is incorrect because the simplification does not yield \(\frac{1}{4}\); the calculations confirm that the result is \(\frac{1}{2}\).
### Revision Summary
- Simplify square roots by factoring out perfect squares.
- Combine like terms in the numerator after simplification.
- Simplify the denominator similarly and cancel common factors.
- The final simplified result of \((\sqrt{98} - \sqrt{50})/\sqrt{32}\) is \(\frac{1}{2}\).