Math Problem Statement

Solve the equation x + 1 - 2√(x + 4) = 0.

Solution

The equation from the image is:

x+12x+4=0x + 1 - 2\sqrt{x + 4} = 0

To solve this, we can follow these steps:

Step 1: Isolate the square root term

Move the other terms to the right-hand side of the equation: 2x+4=x+12\sqrt{x + 4} = x + 1

Step 2: Square both sides

Squaring both sides eliminates the square root: (2x+4)2=(x+1)2(2\sqrt{x + 4})^2 = (x + 1)^2 4(x+4)=(x+1)24(x + 4) = (x + 1)^2

Step 3: Expand both sides

Expand both the left and right-hand sides: 4(x+4)=4x+164(x + 4) = 4x + 16 On the right-hand side: (x+1)2=x2+2x+1(x + 1)^2 = x^2 + 2x + 1

So, the equation becomes: 4x+16=x2+2x+14x + 16 = x^2 + 2x + 1

Step 4: Move all terms to one side

Rearrange the equation to set it equal to 0: 0=x2+2x+14x160 = x^2 + 2x + 1 - 4x - 16 Simplify: x22x15=0x^2 - 2x - 15 = 0

Step 5: Solve the quadratic equation

This is a standard quadratic equation. We can factor it: (x5)(x+3)=0(x - 5)(x + 3) = 0

So, the solutions are: x=5orx=3x = 5 \quad \text{or} \quad x = -3

Step 6: Check for extraneous solutions

Since we squared both sides in the process, we need to check if both solutions are valid by substituting them back into the original equation:

  • For x=5x = 5: 5+125+4=629=66=05 + 1 - 2\sqrt{5 + 4} = 6 - 2\sqrt{9} = 6 - 6 = 0 This is valid.

  • For x=3x = -3: 3+123+4=221=22=4-3 + 1 - 2\sqrt{-3 + 4} = -2 - 2\sqrt{1} = -2 - 2 = -4 This does not satisfy the original equation.

Thus, the only valid solution is: x=5x = 5

Would you like more details or have any questions?

Related Questions:

  1. How do you solve an equation with multiple square root terms?
  2. How does squaring both sides of an equation affect possible solutions?
  3. Can a quadratic equation have more than two solutions?
  4. What are the conditions for a solution to be extraneous?
  5. How can you solve equations with cube roots?

Tip:

Always check for extraneous solutions when solving equations that involve squaring both sides!

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Math Problem Analysis

Mathematical Concepts

Algebra
Radical Equations
Quadratic Equations

Formulas

Radical equation: √(x + a) = b
Quadratic equation: ax^2 + bx + c = 0

Theorems

Quadratic Formula
Properties of Square Roots

Suitable Grade Level

Grades 9-11