Question 282 of 480
What is the simplified form of the expression \(\sqrt{50} + \sqrt{18} - \sqrt{8}\)?
- \(5 + 3\sqrt{2}\)
- \(5 + 2\sqrt{2}\)
- \(7 + 3\sqrt{2}\)
- \(4 + 5\sqrt{2}\)
Correct Answer:
A
Explanation
To simplify the expression \(\sqrt{50} + \sqrt{18} - \sqrt{8}\), we will break down each square root into its simplest form. Let's go through this step-by-step.
### Step 1: Simplifying Each Square Root
1. **Simplifying \(\sqrt{50}\)**:
- We can factor \(50\) into \(25 \times 2\).
- Since \(25\) is a perfect square, we can take the square root of it:
\[
\sqrt{50} = \sqrt{25 \times 2} = \sqrt{25} \cdot \sqrt{2} = 5\sqrt{2}
\]
2. **Simplifying \(\sqrt{18}\)**:
- We can factor \(18\) into \(9 \times 2\).
- Again, \(9\) is a perfect square:
\[
\sqrt{18} = \sqrt{9 \times 2} = \sqrt{9} \cdot \sqrt{2} = 3\sqrt{2}
\]
3. **Simplifying \(\sqrt{8}\)**:
- We can factor \(8\) into \(4 \times 2\).
- Here, \(4\) is also a perfect square:
\[
\sqrt{8} = \sqrt{4 \times 2} = \sqrt{4} \cdot \sqrt{2} = 2\sqrt{2}
\]
### Step 2: Substituting Back into the Expression
Now that we have simplified each square root, we can substitute them back into the original expression:
\[
\sqrt{50} + \sqrt{18} - \sqrt{8} = 5\sqrt{2} + 3\sqrt{2} - 2\sqrt{2}
\]
### Step 3: Combining Like Terms
Next, we combine the terms that contain \(\sqrt{2}\):
- The coefficients of \(\sqrt{2}\) are \(5\), \(3\), and \(-2\):
\[
5 + 3 - 2 = 6
\]
Thus, we have:
\[
5\sqrt{2} + 3\sqrt{2} - 2\sqrt{2} = (5 + 3 - 2)\sqrt{2} = 6\sqrt{2}
\]
### Final Expression
The simplified form of the expression \(\sqrt{50} + \sqrt{18} - \sqrt{8}\) is:
\[
6\sqrt{2}
\]
### Evaluating the Options
Now, let's evaluate the provided options:
- **Option A: \(5 + 3\sqrt{2}\)** - This is incorrect because it does not match our final result of \(6\sqrt{2}\).
- **Option B: \(5 + 2\sqrt{2}\)** - This is also incorrect for the same reason.
- **Option C: \(7 + 3\sqrt{2}\)** - This is incorrect as well.
- **Option D: \(4 + 5\sqrt{2}\)** - This is incorrect too.
None of the options provided match the correct simplified form of \(6\sqrt{2}\).
### Common Pitfalls
- **Not recognizing perfect squares**: It's essential to identify perfect squares when simplifying square roots.
- **Combining terms incorrectly**: Ensure that you only combine like terms (terms that have the same radical part).
- **Forgetting to subtract**: When dealing with subtraction in expressions, be careful to apply it correctly to the coefficients.
### Revision Summary
- Simplify square roots by factoring out perfect squares.
- Combine like terms carefully, ensuring to account for addition and subtraction.
- Always check your final answer against the options provided to ensure accuracy.
- Practice simplifying various square root expressions to build confidence.