Algebra II
Advanced algebraic concepts including polynomials, rational expressions, and complex numbers.
Rational Expressions and Equations
Working with Rational Expressions
Rational expressions are fractions with polynomials in the numerator and denominator. You can simplify, multiply, divide, add, or subtract them—just like with numerical fractions!
Simplifying
Factor both the numerator and denominator and cancel any common factors. Always check for restrictions—values that would make the denominator zero.
Solving Rational Equations
To solve equations with rational expressions, find a common denominator, multiply both sides to eliminate denominators, then solve the resulting equation.
Why Rational Expressions Matter
Rational expressions are used in everything from calculating speed to understanding rates in chemistry.
Applications
Rational equations can describe things like mixing solutions, comparing speeds, or sharing resources.
Examples
Simplifying \( \frac{x^2 - 4}{x^2 - 2x} = \frac{(x + 2)(x - 2)}{x(x - 2)} = \frac{x + 2}{x} \) (as long as \( x \neq 0, 2 \))
Solving \( \frac{1}{x} + \frac{1}{2} = 1 \) gives \( x = 2 \ )
In a Nutshell
Rational expressions are fractions made from polynomials, and can be simplified or solved like regular fractions.