Verified Answer :

  • To divide the rational expressions, rewrite the division as multiplication by the reciprocal of the second fraction: \(\frac{x+1}{x^2+5x+6} \cdot \frac{x^2+2x-3}{3x+3}\).
  • Factor all quadratic and linear terms to get \(\frac{x+1}{(x+2)(x+3)} \cdot \frac{(x+3)(x-1)}{3(x+1)}\).
  • Identify and cancel the common factors \((x+1)\) and \((x+3)\) from the numerator and denominator.
  • The final simplified expression is \(\boxed{\frac{x-1}{3(x+2)}}\).

Explanation

  1. Problem Analysis and Strategy

We are asked to simplify the division of two rational expressions:
\[\frac{x+1}{x^2+5x+6} \div \frac{3x+3}{x^2+2x-3}\]
A rational expression is a fraction where the numerator and denominator are polynomials. Dividing by a fraction is equivalent to multiplying by its reciprocal. Our goal is to factor each component and simplify the resulting expression.

  1. Factoring and Substitution

To divide by a fraction, we multiply by its reciprocal:
\[\frac{x+1}{x^2+5x+6} \cdot \frac{x^2+2x-3}{3x+3}\]
Next, we factor each polynomial involved:

  1. The denominator \(x^2+5x+6\) factors as \((x+2)(x+3)\).
  2. The numerator \(x^2+2x-3\) factors as \((x+3)(x-1)\).
  3. The denominator \(3x+3\) factors as \(3(x+1)\).

Substituting these factored forms into our expression gives:
\[\frac{x+1}{(x+2)(x+3)} \cdot \frac{(x+3)(x-1)}{3(x+1)}\]

  1. Simplification and Final Result

Now, we look for common factors in the numerator and denominator:
\[\frac{(x+1)(x+3)(x-1)}{(x+2)(x+3) \cdot 3(x+1)}\]
We can cancel the common factors \((x+1)\) and \((x+3)\), provided they are not equal to zero. This leaves us with:
\[\frac{x-1}{3(x+2)}\]
This is the most simplified form of the given expression.

Examples

Simplifying rational expressions is fundamental in fields like physics and engineering, where complex formulas are reduced to manageable forms. For instance, when analyzing the resistance in a parallel electrical circuit or calculating the velocity of an object over time, you often encounter rational expressions. Reducing these expressions allows for easier calculations, better insight into the relationship between variables, and faster analysis of real-world phenomena.