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Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 2, Problem 64

Solve each equation using the quadratic formula. See Examples 5 and 6.
(3x+2)(x1)=3x(3x + 2)(x - 1) = 3x

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1
First, expand the left side of the equation by using the distributive property: multiply each term in the first binomial by each term in the second binomial. This gives you \( (3x + 2)(x - 1) = 3x \cdot x + 3x \cdot (-1) + 2 \cdot x + 2 \cdot (-1) \).
Simplify the expression from the expansion to get a quadratic expression on the left side: \( 3x^2 - 3x + 2x - 2 \).
Combine like terms on the left side to simplify further: \( 3x^2 - x - 2 \).
Rewrite the original equation by setting it equal to zero: \( 3x^2 - x - 2 = 3x \). Then subtract \( 3x \) from both sides to get \( 3x^2 - x - 2 - 3x = 0 \), which simplifies to \( 3x^2 - 4x - 2 = 0 \).
Identify the coefficients for the quadratic formula: \( a = 3 \), \( b = -4 \), and \( c = -2 \). Then write down the quadratic formula: \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \). Substitute the values of \( a \), \( b \), and \( c \) into the formula to prepare for solving.

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Key Concepts

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

Quadratic Equations

A quadratic equation is a polynomial equation of degree two, generally written as ax² + bx + c = 0. Understanding how to rewrite equations into this standard form is essential before applying methods like the quadratic formula.
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Expanding and Simplifying Expressions

To solve the given equation, you must first expand the product (3x + 2)(x - 1) and then simplify the resulting expression. This step helps in rearranging the equation into the standard quadratic form.
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Expanding Radicals

Quadratic Formula

The quadratic formula x = [-b ± √(b² - 4ac)] / (2a) provides the solutions to any quadratic equation ax² + bx + c = 0. It requires identifying coefficients a, b, and c correctly and calculating the discriminant to find real or complex roots.
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