Extracting Square Roots Practice Problems & Solutions

Master quadratic equations by extracting square roots with step-by-step practice problems. Learn to solve x² - c = 0 equations efficiently and avoid common mistakes.

📚Master Square Root Extraction with Interactive Practice
  • Solve quadratic equations of the form x² - c = 0 using square root extraction
  • Master the three-step process: isolate x², take square roots, write solutions
  • Handle coefficients greater than 1 by dividing to isolate x² completely
  • Recognize when equations have no solution due to negative square roots
  • Work with fractional and radical solutions confidently
  • Apply the ± symbol correctly when extracting square roots

Understanding Extracting Square Roots

Complete explanation with examples

Solution by extracting a root

Solving a quadratic equation with one variable X2c=0X^2-c=0 (where b=0b=0) by calculating the square root:

First step

Moving terms and isolating X2X^2.

Second stage

Take the square root of both sides. Don't forget to insert ±\pm before the square root of the free term.

Third stage

Writing solutions in an organized manner or writing "no solution" in case of a root of a negative number.

Detailed explanation

Practice Extracting Square Roots

Test your knowledge with 15 quizzes

Solve the following equation

\( x^2-25=0 \)

Examples with solutions for Extracting Square Roots

Step-by-step solutions included
Exercise #1

Solve the following exercise:

2x28=x2+4 2x^2-8=x^2+4

Step-by-Step Solution

First, we move the terms to one side equal to 0.

2x2x284=0 2x^2-x^2-8-4=0

We simplify :

x212=0 x^2-12=0

We use the shortcut multiplication formula to solve:

x2(12)2=0 x^2-(\sqrt{12})^2=0

(x12)(x+12)=0 (x-\sqrt{12})(x+\sqrt{12})=0

x=±12 x=\pm\sqrt{12}

Answer:

±12 ±\sqrt{12}

Video Solution
Exercise #2

Solve the following exercise:

x220=5 x^2-20=5

Step-by-Step Solution

To solve this quadratic equation x220=5 x^2 - 20 = 5 , we will follow these steps:

  • Step 1: First, add 20 to both sides of the equation to isolate the x2 x^2 term:

x220+20=5+20 x^2 - 20 + 20 = 5 + 20

This simplifies to:

x2=25 x^2 = 25

  • Step 2: Next, take the square root of both sides to solve for x x :

x=±25 x = \pm \sqrt{25}

x=±5 x = \pm 5

Therefore, the solutions to the equation are:

x=5 x = 5 and x=5 x = -5

Thus, the correct answer choice is:

  • ±5 \pm 5 from the provided options.

The correct solution to the problem is ±5 \pm 5 .

Answer:

±5

Video Solution
Exercise #3

Solve for X:

xx=49 x\cdot x=49

Step-by-Step Solution

We first rearrange and then set the equations to equal zero.

x249=0 x^2-49=0

x272=0 x^2-7^2=0

We use the abbreviated multiplication formula:

(x7)(x+7)=0 (x-7)(x+7)=0

x=±7 x=\pm7

Answer:

±7

Video Solution
Exercise #4

Solve the following:

x2+x23=x2+6 x^2+x^2-3=x^2+6

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Simplify the given equation.
  • Solve for x2 x^2 and find x x .

First, let's simplify the equation:

x2+x23=x2+6 x^2 + x^2 - 3 = x^2 + 6 .

Combine like terms on the left side:

2x23=x2+6 2x^2 - 3 = x^2 + 6 .

Subtract x2 x^2 from both sides to isolate one of the x x terms:

2x2x23=6 2x^2 - x^2 - 3 = 6 .

This simplifies to:

x23=6 x^2 - 3 = 6 .

Next, add 3 to both sides to solve for x2 x^2 :

x2=9 x^2 = 9 .

To find x x , take the square root of both sides:

x=±9 x = \pm\sqrt{9} .

This results in:

x=±3 x = \pm3 .

Therefore, the solution to the problem is ±3\pm3.

Answer:

±3

Video Solution
Exercise #5

Solve the following equation:

4x2+8+2x=x+12+x 4x^2+8+2x=x+12+x

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Simplify both sides of the equation.
  • Step 2: Rearrange terms to form a quadratic equation.
  • Step 3: Solve the quadratic equation using an appropriate method, such as factoring or applying the quadratic formula.

Now, let's work through each step:

Step 1: Simplify both sides of the equation:

4x2+8+2x=x+12+x 4x^2 + 8 + 2x = x + 12 + x

The right-hand side can be simplified:

x+x+12=2x+12 x + x + 12 = 2x + 12

This yields the equation:

4x2+8+2x=2x+12 4x^2 + 8 + 2x = 2x + 12

Step 2: Rearrange the terms to form a quadratic equation. Subtract 2x+12 2x + 12 from both sides:

4x2+8+2x2x12=0 4x^2 + 8 + 2x - 2x - 12 = 0

Combining like terms gives:

4x24=0 4x^2 - 4 = 0

Step 3: Solve the resulting quadratic equation:

First, we add 4 to both sides:

4x2=4 4x^2 = 4

Next, divide both sides by 4:

x2=1 x^2 = 1

Now, apply the square root to both sides:

x=±1 x = \pm 1

Therefore, the solutions to the quadratic equation are

x=±1 x = \pm 1 .

The correct answer is choice 2: ±1.

Answer:

±1

Video Solution

Frequently Asked Questions

What is the square root extraction method for quadratic equations?

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The square root extraction method is used to solve quadratic equations of the form x² - c = 0 (where b = 0). It involves three steps: isolate x² on one side, take the square root of both sides with ± symbol, and write the two solutions clearly.

When can I use square root extraction instead of the quadratic formula?

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Use square root extraction when your quadratic equation has no middle term (b = 0) and looks like ax² + c = 0. This method is much faster than the quadratic formula for these specific equations.

Why do I need to use ± when extracting square roots?

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The ± symbol is essential because every positive number has two square roots: one positive and one negative. For example, both 4 and -4 when squared equal 16, so x = ±4 gives you both solutions.

What happens if I get a negative number under the square root?

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If you need to find the square root of a negative number, the equation has no real solution. You cannot find a real number that when squared gives a negative result, so write 'no solution' as your answer.

How do I handle coefficients in front of x² when extracting square roots?

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First divide both sides by the coefficient to completely isolate x². For example, with 3x² = 9, divide both sides by 3 to get x² = 3, then take the square root: x = ±√3.

Should I simplify square roots in my final answer?

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Yes, always simplify square roots when possible. For example, √16 should be written as 4, not left as √16. However, if the square root cannot be simplified to a whole number, it's acceptable to leave it in radical form.

What are the most common mistakes when extracting square roots?

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Common mistakes include: 1) Forgetting the ± symbol, 2) Not completely isolating x² before taking the square root, 3) Trying to find the square root of a negative number instead of writing 'no solution', and 4) Not simplifying final answers when possible.

Can I use square root extraction for equations like x² + 4 = 0?

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Yes, you can apply the method, but this specific equation has no real solution. After isolating x², you get x² = -4, and since you cannot take the square root of a negative number, the answer is 'no solution'.

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