Solve the Radical Equation: Find X in x + √x = -√x

Radical Equations with Extraneous Solutions

Solve for X:

x+x=x x+\sqrt{x}=-\sqrt{x}

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Find X
00:03 Isolate X
00:09 Collect terms
00:18 Factor X into root X and root X
00:28 Find common factor and take out of parentheses
00:37 Find the two solutions that zero the equation
00:43 This is one solution
00:50 Now let's find the second solution
01:00 The root result must always be positive
01:06 And this is the solution to the problem

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Solve for X:

x+x=x x+\sqrt{x}=-\sqrt{x}

2

Step-by-step solution

To solve the equation x+x=x x + \sqrt{x} = -\sqrt{x} , we follow these steps:

  • Step 1: Simplify the equation by combining like terms. We have: x+x=xx+2x=0 x + \sqrt{x} = -\sqrt{x} \Rightarrow x + 2\sqrt{x} = 0
  • Step 2: Isolate x x by rearranging terms: x=2x x = -2\sqrt{x}
  • Step 3: Square both sides to eliminate the square root: x2=4x x^2 = 4x
  • Step 4: Rearrange the equation into standard quadratic form: x24x=0 x^2 - 4x = 0
  • Step 5: Factor the quadratic equation: x(x4)=0 x(x - 4) = 0
  • Step 6: Solve for x x : x=0orx=4 x = 0 \quad \text{or} \quad x = 4

Step 7: Verify each solution in the original equation. We find:

  • For x=0 x = 0 : 0+0=0 0 + \sqrt{0} = -\sqrt{0} 0=0True 0 = 0 \quad \text{True}
  • For x=4 x = 4 : 4+4=4 4 + \sqrt{4} = -\sqrt{4} 4+22False 4 + 2 \neq -2 \quad \text{False}

Thus, the only valid solution is x=0 x = 0 .

Therefore, the solution to the equation is x=0 x = 0 , which corresponds to choice 2.

3

Final Answer

0 0

Key Points to Remember

Essential concepts to master this topic
  • Domain Restriction: Square root arguments must be non-negative for real solutions
  • Technique: Add like terms first: x+x=2x \sqrt{x} + \sqrt{x} = 2\sqrt{x}
  • Check: Always verify solutions in original equation to catch extraneous solutions ✓

Common Mistakes

Avoid these frequent errors
  • Forgetting to verify solutions after squaring
    Don't assume both solutions from x(x-4)=0 are valid = accepting x=4 as correct! Squaring both sides can introduce extraneous solutions that don't work in the original equation. Always substitute each solution back into the original radical equation to verify.

Practice Quiz

Test your knowledge with interactive questions

Choose the expression that has the same value as the following:

\( (x+y)^2 \)

FAQ

Everything you need to know about this question

Why do I need to check my answers when solving radical equations?

+

When you square both sides to eliminate radicals, you can accidentally create extra solutions that don't work in the original equation. These are called extraneous solutions and must be rejected!

What does the domain restriction x ≥ 0 mean?

+

For x \sqrt{x} to have real values, we need x ≥ 0. You can't take the square root of negative numbers in the real number system, so any negative solutions must be discarded.

How do I combine the square root terms correctly?

+

Think of x \sqrt{x} like a variable. Just like x + x = 2x, we have x+x=2x \sqrt{x} + \sqrt{x} = 2\sqrt{x} . Move all radical terms to one side first!

Why doesn't x = 4 work as a solution?

+

Let's check: 4+4=4 4 + \sqrt{4} = -\sqrt{4} becomes 4 + 2 = -2, which gives us 6 = -2. This is false! So x = 4 is an extraneous solution introduced by squaring.

Can radical equations have no solutions?

+

Yes! Sometimes after checking, all potential solutions turn out to be extraneous. In such cases, we say the equation has no solution or the solution set is empty.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Short Multiplication Formulas questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations