Ch. 1 - Equations and Inequalities

Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook

Blitzer 8th Edition

Ch. 1 - Equations and Inequalities

Problem 34a

Chapter 2, Problem 34a

Solve each equation in Exercises 15–34 by the square root property. (2x + 8)² = 27

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Start by applying the square root property to both sides of the equation. The square root property states that if $(a)^2 = b$, then $a = \pm \sqrt{b}$. For this problem, take the square root of both sides: $\sqrt{(2x + 8)^2} = \pm \sqrt{27}$.

Simplify the left-hand side of the equation. The square root of $(2x + 8)^2$ is $2x + 8$. On the right-hand side, simplify $\sqrt{27}$ into its simplest radical form: $\sqrt{27} = \sqrt{9 \cdot 3} = 3\sqrt{3}$. The equation now becomes $2x + 8 = \pm 3\sqrt{3}$.

Isolate $2x$ by subtracting 8 from both sides of the equation: $2x = -8 \pm 3\sqrt{3}$.

Divide both sides of the equation by 2 to solve for $x$: $x = \frac{-8 \pm 3\sqrt{3}}{2}$.

Express the solution as two separate values: $x = \frac{-8 + 3\sqrt{3}}{2}$ and $x = \frac{-8 - 3\sqrt{3}}{2}$. These are the two solutions to the equation.

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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 a quadratic equation is in the form (ax + b)^2 = c, then the solutions can be found by taking the square root of both sides. This leads to two possible equations: ax + b = √c and ax + b = -√c. This property is essential for solving equations that can be expressed as perfect squares.

Isolating the Variable

Isolating the variable involves rearranging the equation to get the variable on one side and the constants on the other. In the context of the square root property, this often means simplifying the equation to the form (ax + b)^2 = c before applying the square root. This step is crucial for accurately finding the values of the variable.

Extraneous Solutions

Extraneous solutions are solutions that emerge from the algebraic process but do not satisfy the original equation. When using the square root property, it is important to check each potential solution by substituting it back into the original equation to ensure it is valid. This helps avoid incorrect conclusions that may arise from the algebraic manipulation.

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Solve each equation in Exercises 15–34 by the square root property. (2x + 8)2 = 27

Verified video answer for a similar problem:

Key Concepts

Square Root Property

Isolating the Variable

Extraneous Solutions

Solve each equation in Exercises 15–34 by the square root property. (2x + 8)² = 27