Chapter 6: Problem 80
Perform the indicated operations. $$\frac{9 w^{2}-64}{3 w^{2}-5 w-8} \cdot \frac{5 w^{2}+3 w-2}{25 w^{2}-4}$$
Short Answer
Expert verified
\( \frac{(3w-8)(3w+8)(w+1)}{(3w+4)(w-2)(5w+2)} \)
Step by step solution
01
- Factorize the Numersator and Denominator of First Fraction
The first fraction given is \ \( \frac{9w^{2}-64}{3w^{2}-5w-8} \ \). Factorize the numerator and the denominator separately:- Numerator: Recognize the difference of squares: \ \( 9w^2-64 = (3w)^2 - 8^2 = (3w-8)(3w+8) \ \)- Denominator: Factorize by splitting the middle term: \ \( 3w^{2}-5w-8 = (3w+4)(w-2) \ \)
02
- Factorize the Numerator and Denominator of Second Fraction
The second fraction given is \ \( \frac{5w^2 + 3w - 2}{25w^2 - 4} \ \). Factorize the numerator and the denominator separately:- Numerator: Factor by splitting the middle term: \ \( 5w^2 + 3w - 2 = (5w - 2)(w + 1) \ \)- Denominator: Recognize the difference of squares: \ \( 25w^2 - 4 = (5w)^2 - 2^2 = (5w-2)(5w+2) \ \)
03
- Rewrite the Expression with Factored Forms
Substitute the factored forms into the original expression:\ \(\frac{(3w-8)(3w+8)}{(3w+4)(w-2)} \cdot \frac{(5w-2)(w+1)}{(5w-2)(5w+2)}\ \)
04
- Cancel Common Factors
Identify and cancel common factors in the numerator and denominator:- Common factors: \ \( 5w-2 \ \)(Remove \ \( 5w-2 \ \) from both the numerator and denominator):\ \(\frac{(3w-8)(3w+8)}{(3w+4)(w-2)} \cdot \frac{(w+1)}{(5w+2)}\ \)
05
- Multiply the Remaining Terms
Multiply the remaining terms in the numerator and the denominator: \ \( \frac{(3w-8)(3w+8)(w+1)}{(3w+4)(w-2)(5w+2)} \ \)
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Factoring Polynomials
Factoring polynomials is akin to breaking down a number into its prime components, but in algebraic terms. The goal is to express a polynomial as a product of simpler polynomials. For instance, consider the polynomial \( 3w^2 - 5w - 8 \). To factor this, we look for two binomials whose product gives the original polynomial.
First, identify two numbers that multiply to \( ac \) (where \( a \) is the coefficient of \( w^2 \) and \( c \) is the constant term) and add to \( b \) (the coefficient of \( w \)).
First, identify two numbers that multiply to \( ac \) (where \( a \) is the coefficient of \( w^2 \) and \( c \) is the constant term) and add to \( b \) (the coefficient of \( w \)).
- Here, \( ac = 3 \, -8 = -24 \) and \( b = -5 \).
- The numbers \( -8 \) and \( 3 \) fit since \( -8 * 3 = -24 \) and \( -8 + 3 = -5 \).
Difference of Squares
The difference of squares is a special factoring rule used when a polynomial is in the form \( a^2 - b^2 \). The formula is \(a^2 - b^2 = (a - b)(a + b) \).
Let's take \( 9w^2 - 64 \) from the original exercise. Notice that both terms, \( 9w^2 \) and \( 64 \), are perfect squares:
Let's take \( 9w^2 - 64 \) from the original exercise. Notice that both terms, \( 9w^2 \) and \( 64 \), are perfect squares:
- \( 9w^2 \) is \( (3w)^2 \)
- \( 64 \) is \( 8^2 \)
Rational Expressions Multiplication
Multiplying rational expressions involves multiplying the numerators together and the denominators together. However, simplifying before multiplying can save significant effort.
Let's revisit the given problem:\( \frac{(3w-8)(3w+8)}{(3w+4)(w-2)} \cdot \frac{(5w-2)(w+1)}{(5w-2)(5w+2)} \).
Before multiplying, eliminate any common factors present in both the numerators and denominators.
Let's revisit the given problem:\( \frac{(3w-8)(3w+8)}{(3w+4)(w-2)} \cdot \frac{(5w-2)(w+1)}{(5w-2)(5w+2)} \).
Before multiplying, eliminate any common factors present in both the numerators and denominators.
- Here, \( 5w - 2 \) is a common factor
- After canceling out, we get: \( \frac{(3w-8)(3w+8)}{(3w+4)(w-2)} \cdot \frac{(w+1)}{(5w+2)} \).