When the sum of 6 and twice a positive number is subtracted from the square of the number, 0 results. Find the number.
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- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
Intro to Quadratic Equations
Problem 61
Textbook Question
Solve each equation by the square root property.
Verified step by step guidance1
Start with the given equation: \(\frac{x^2}{2} + 5 = -3\).
Isolate the term containing \(x^2\) by subtracting 5 from both sides: \(\frac{x^2}{2} = -3 - 5\).
Simplify the right side: \(\frac{x^2}{2} = -8\).
Eliminate the fraction by multiplying both sides of the equation by 2: \(x^2 = -16\).
Apply the square root property: take the square root of both sides, remembering to include both the positive and negative roots: \(x = \pm \sqrt{-16}\).
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Square Root Property
The square root property states that if x² = k, then x = ±√k. This method is used to solve quadratic equations that can be written in the form x² = a constant. It simplifies solving by isolating the squared term and then taking the square root of both sides.
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Isolating the Variable Term
Before applying the square root property, the equation must be manipulated to isolate the squared term on one side. This involves using algebraic operations such as addition, subtraction, multiplication, or division to simplify the equation and prepare it for taking square roots.
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Equations with Two Variables
Handling Negative Values Under the Square Root
If the value under the square root (the radicand) is negative, the solutions involve imaginary or complex numbers. Recognizing when the radicand is negative is important, as it indicates no real solutions exist, and the answer must be expressed using the imaginary unit i, where i² = -1.
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