Algebra 2 Common Core

Published by Prentice Hall
ISBN 10: 0133186024
ISBN 13: 978-0-13318-602-4

Chapter 8 - Rational Functions - 8-5 Adding and Subtracting Rational Expressions - Practice and Problem-Solving Exercises - Page 541: 54

Answer

$\dfrac{3(x + 2)}{4(x - 3)}$ Restrictions: $x \ne -2, 2, 3$

Work Step by Step

First, factor all expressions in the original exercise: $\dfrac{3(x - 2)}{12(x - 2)} \div \dfrac{(x - 3)(x - 2)}{3(x - 2)(x + 2)}$ To divide one fraction by another, multiply the first fraction by the reciprocal of the second fraction: $\dfrac{3(x - 2)}{12(x - 2)} \cdot \dfrac{3(x - 2)(x + 2)}{(x - 3)(x - 2)}$ Multiply numerator with numerator and denominator with denominator: $\dfrac{3(x - 2)\cdot 3(x - 2)(x + 2)}{12(x - 2) \cdot (x - 3)(x - 2)}$ Cancel common terms in the numerator and denominator: $\require{cancel} \dfrac{\cancel{3}\cancel{(x - 2)}\cdot 3\cancel{(x - 2)}(x + 2)}{^4\cancel{12}\cancel{(x - 2)} \cdot (x - 3)\cancel{(x - 2)}}$ $=\dfrac{3(x + 2)}{4(x - 3)}$ Restrictions on $x$ occur when the value of $x$ makes the fraction undefined, which means that the denominator becomes $0$. Set denominators equal to $0$ and solve for $x$ to find where the restrictions are: First denominator: $12x - 24 = 0$ $12x = 24$ $x = 2$ Second denominator: $3x^2 - 12 = 0$ $3x^2 = 12$ $x^2 = 4$ Take the square root of each side of the equation: $x = \pm 2$ Third denominator (from the reciprocal): $x - 3 = 0$ $x = 3$ $x - 2 = 0$ $x = 2$ Restrictions: $x \ne -2, 2, 3$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.