Math Problem Statement

Simplify the rational division: (-4x / (x - 7)) ÷ ((x^2 - 12x + 36) / (2x - 14)). What is the quotient in lowest terms? What values of x must be excluded from the domain?

Solution

Let's break down the problem step by step.

Given Expression:

You need to simplify the rational division:

4xx7÷x212x+362x14\frac{-4x}{x - 7} \div \frac{x^2 - 12x + 36}{2x - 14}

Step 1: Change Division to Multiplication

Dividing by a fraction is equivalent to multiplying by its reciprocal. So, we rewrite the expression as:

4xx7×2x14x212x+36\frac{-4x}{x - 7} \times \frac{2x - 14}{x^2 - 12x + 36}

Step 2: Factorize Terms

  • Factorize x212x+36x^2 - 12x + 36: x212x+36=(x6)(x6)x^2 - 12x + 36 = (x - 6)(x - 6)

  • Factorize 2x142x - 14: 2x14=2(x7)2x - 14 = 2(x - 7)

Now, the expression becomes:

4xx7×2(x7)(x6)(x6)\frac{-4x}{x - 7} \times \frac{2(x - 7)}{(x - 6)(x - 6)}

Step 3: Simplify

  • Cancel the common factor x7x - 7 from both the numerator and the denominator: 4x1×2(x6)(x6)\frac{-4x}{1} \times \frac{2}{(x - 6)(x - 6)} This simplifies to: 8x(x6)2\frac{-8x}{(x - 6)^2}

Step 4: Domain Restrictions

  • The domain excludes values where the denominator is zero. From the expression (x6)2(x - 6)^2, we know that x=6x = 6 must be excluded from the domain.
  • Additionally, from the original denominators x7x - 7 and 2x14=2(x7)2x - 14 = 2(x - 7), we exclude x=7x = 7.

Thus, the values that must be excluded from the domain are x=6x = 6 and x=7x = 7.

Final Answers:

  1. The quotient in lowest terms is: 8x(x6)2\frac{-8x}{(x - 6)^2}

  2. The values of xx to exclude from the domain are: x=6,x=7x = 6, x = 7


Would you like a more detailed explanation of any step? Here are some related questions you can explore:

  1. What happens when dividing two rational expressions?
  2. How do you find the domain of a rational expression?
  3. How do you factor quadratic expressions like x212x+36x^2 - 12x + 36?
  4. Why does division by zero affect the domain?
  5. What is the significance of canceling terms in rational expressions?

Tip: Always check for factors in both the numerator and denominator that can simplify your rational expressions!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Rational Expressions
Division of Fractions
Factoring Quadratics
Simplifying Expressions
Domain Restrictions

Formulas

Division of fractions: (a/b) ÷ (c/d) = (a/b) × (d/c)
Factoring: x^2 - 12x + 36 = (x - 6)(x - 6)
Domain restrictions: Denominators must not be zero

Theorems

Rational expression simplification
Zero Product Property

Suitable Grade Level

Grades 9-12