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Ch. 4 - Exponential and Logarithmic Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 5, Problema 138

Exercises 137–139 will help you prepare for the material covered in the next section. Solve: x(x - 7) = 3.

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Start by expanding the left side of the equation: x(x-7) = x⋅x - x⋅7 = x2 - 7x.
Rewrite the equation with the expanded form: x2 - 7x = 3.
Bring all terms to one side to set the equation equal to zero: x2 - 7x - 3 = 0.
Identify the coefficients for the quadratic equation in standard form ax^2 + bx + c = 0: here, a = 1, b = -7, and c = -3.
Use the quadratic formula to solve for x: x = \(\frac{-b \pm \sqrt{b^2 - 4ac}\)}{2a}. Substitute the values of a, b, and c into the formula.

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Expanding and Simplifying Algebraic Expressions

This involves applying the distributive property to multiply terms within parentheses and then combining like terms. For example, expanding x(x - 7) results in x² - 7x, which simplifies the equation for easier manipulation.
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Simplifying Algebraic Expressions

Solving Quadratic Equations

Quadratic equations are polynomial equations of degree two, typically in the form ax² + bx + c = 0. Solving them can involve factoring, completing the square, or using the quadratic formula to find the values of x that satisfy the equation.
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Setting Equations to Zero

To solve quadratic equations, it is essential to rewrite the equation so that one side equals zero. This allows the use of factoring or the quadratic formula by isolating all terms on one side, creating a standard form ax² + bx + c = 0.
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Finding Zeros & Their Multiplicity