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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 100

In Exercises 91–100, find all values of x satisfying the given conditions.y1=6(2xx3)2,y2=5(2xx3),andy1 exceeds y2 by 6.y_1 = 6 \(\left\)( \(\frac{2x}{x - 3}\) \(\right\))^2, \(\quad\) y_2 = 5 \(\left\)( \(\frac{2x}{x - 3}\) \(\right\)), \(\quad\) \(\text{and}\) \(\quad\) y_1 \(\text{ exceeds }\) y_2 \(\text{ by }\) 6.

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Start by translating the condition "y1 exceeds y2 by 6" into an equation. This means that y1 is equal to y2 plus 6, so write: \(y_1 = y_2 + 6\).
Substitute the given expressions for \(y_1\) and \(y_2\) into the equation: \(6\left(\frac{2x}{x - 3}\right)^2 = 5\left(\frac{2x}{x - 3}\right) + 6\).
To simplify the equation, let \(t = \frac{2x}{x - 3}\). Rewrite the equation in terms of \(t\): \(6t^2 = 5t + 6\).
Rearrange the equation to standard quadratic form: \(6t^2 - 5t - 6 = 0\).
Solve the quadratic equation for \(t\) using the quadratic formula: \(t = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\), where \(a=6\), \(b=-5\), and \(c=-6\). After finding the values of \(t\), substitute back \(t = \frac{2x}{x - 3}\) and solve for \(x\).

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Key Concepts

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

Rational Expressions

Rational expressions are fractions where the numerator and denominator are polynomials. Understanding how to simplify, manipulate, and evaluate these expressions is essential, especially when variables appear in denominators, as restrictions on the domain must be considered to avoid division by zero.
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