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Ch. 1 - Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 2, Problem 55

Solve each equation in Exercises 47–64 by completing the square. x25x+6=0x^2 - 5x + 6 = 0

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1
Start with the given quadratic equation: \(x^2 - 5x + 6 = 0\).
Move the constant term to the other side to isolate the quadratic and linear terms: \(x^2 - 5x = -6\).
To complete the square, take half of the coefficient of \(x\), which is \(-5\), divide by 2 to get \(-\frac{5}{2}\), then square it to get \(\left(-\frac{5}{2}\right)^2 = \frac{25}{4}\).
Add \(\frac{25}{4}\) to both sides of the equation to maintain equality: \(x^2 - 5x + \frac{25}{4} = -6 + \frac{25}{4}\).
Rewrite the left side as a perfect square trinomial: \(\left(x - \frac{5}{2}\right)^2 = -6 + \frac{25}{4}\). From here, you can simplify the right side and solve for \(x\) by taking the square root of both sides.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Completing the Square

Completing the square is a method used to solve quadratic equations by transforming the equation into a perfect square trinomial. This involves adding and subtracting a specific value to create a binomial squared, making it easier to solve for the variable.
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Quadratic Equations

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Solving Equations Using Square Roots

Once a quadratic equation is written as a perfect square equal to a constant, you can solve it by taking the square root of both sides. This step introduces both positive and negative roots, which are critical for finding all solutions.
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