Math Problem Statement

Solve the equation: \(\sqrt{3 - x} - \sqrt{7 + x} = \sqrt{16 + 2x}\)

Solution

The equation in the image is:

3x7+x=16+2x\sqrt{3 - x} - \sqrt{7 + x} = \sqrt{16 + 2x}

Let's solve this step by step.

Step 1: Isolate one of the square root terms

Move 7+x\sqrt{7 + x} to the right-hand side:

3x=16+2x+7+x\sqrt{3 - x} = \sqrt{16 + 2x} + \sqrt{7 + x}

Step 2: Square both sides to eliminate the square root

Squaring both sides will help us remove the square root on the left side.

(3x)2=(16+2x+7+x)2(\sqrt{3 - x})^2 = (\sqrt{16 + 2x} + \sqrt{7 + x})^2

This simplifies to:

3x=(16+2x)+(7+x)+2(16+2x)(7+x)3 - x = (16 + 2x) + (7 + x) + 2\sqrt{(16 + 2x)(7 + x)}

Simplify the equation:

3x=23+3x+2(16+2x)(7+x)3 - x = 23 + 3x + 2\sqrt{(16 + 2x)(7 + x)}

Step 3: Isolate the square root again

Subtract 23+3x23 + 3x from both sides:

204x=2(16+2x)(7+x)-20 - 4x = 2\sqrt{(16 + 2x)(7 + x)}

Step 4: Square both sides again

Square both sides to eliminate the square root:

(204x)2=4[(16+2x)(7+x)](-20 - 4x)^2 = 4[(16 + 2x)(7 + x)]

Step 5: Expand and simplify

Expand both sides:

400+160x+16x2=4[(16)(7)+16x+14x+2x2]400 + 160x + 16x^2 = 4[(16)(7) + 16x + 14x + 2x^2]

Simplify:

400+160x+16x2=4[112+30x+2x2]400 + 160x + 16x^2 = 4[112 + 30x + 2x^2]

Further simplifying:

400+160x+16x2=448+120x+8x2400 + 160x + 16x^2 = 448 + 120x + 8x^2

Step 6: Bring all terms to one side

16x28x2+160x120x+400448=016x^2 - 8x^2 + 160x - 120x + 400 - 448 = 0

8x2+40x48=08x^2 + 40x - 48 = 0

Step 7: Solve the quadratic equation

Divide the entire equation by 8:

x2+5x6=0x^2 + 5x - 6 = 0

Factorize the quadratic equation:

(x+6)(x1)=0(x + 6)(x - 1) = 0

So, the solutions for xx are:

x=6orx=1x = -6 \quad \text{or} \quad x = 1

Step 8: Check the solutions in the original equation

  1. For x=6x = -6:

3(6)7+(6)=16+2(6)\sqrt{3 - (-6)} - \sqrt{7 + (-6)} = \sqrt{16 + 2(-6)}

Simplifies to:

91=4\sqrt{9} - \sqrt{1} = \sqrt{4}

31=2(True)3 - 1 = 2 \quad \text{(True)}

  1. For x=1x = 1:

317+1=16+2(1)\sqrt{3 - 1} - \sqrt{7 + 1} = \sqrt{16 + 2(1)}

Simplifies to:

2818\sqrt{2} - \sqrt{8} \neq \sqrt{18}

This is not true.

Final Answer:

The valid solution is x=6x = -6.

Would you like more details or have any questions? Here are some related questions for further practice:

  1. How do you square both sides of an equation correctly?
  2. What is the importance of checking solutions in the original equation?
  3. How do you factorize a quadratic equation?
  4. What are the common mistakes to avoid when solving equations involving square roots?
  5. How does squaring both sides affect the solutions?

Tip: When dealing with square roots, always check your solutions in the original equation to avoid extraneous solutions.

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Math Problem Analysis

Mathematical Concepts

Algebra
Square Roots
Quadratic Equations

Formulas

Square both sides of the equation
Quadratic equation formula \(ax^2 + bx + c = 0\)

Theorems

Basic Algebraic Operations
Quadratic Formula Theorem

Suitable Grade Level

Grades 10-12