Algebra II

Advanced algebraic concepts including polynomials, rational expressions, and complex numbers.

Basic Concepts

Rational Expressions and Equations

What Are Rational Expressions?

Rational expressions are fractions where both the numerator and the denominator are polynomials. They look like \( \frac{x + 2}{x - 1} \).

Simplifying and Operations

  • Simplify: Cancel out common factors in the numerator and denominator.
  • Add/Subtract: Find a common denominator before combining.
  • Multiply/Divide: Multiply straight across, but remember to factor first for easier cancellation.

Solving Rational Equations

Set the rational expression equal to a number or another rational expression, clear denominators, and solve the resulting equation.

Watch Out!

Check for restrictions: denominators can never be zero.

Examples

  • \( \frac{x^2 - 4}{x - 2} = \frac{(x + 2)(x - 2)}{x - 2} = x + 2 \) (for \( x eq 2 \))

  • To solve \( \frac{2}{x} = 4 \), multiply both sides by \( x \) to get \( x = \frac{2}{4} = 0.5 \).

In a Nutshell

Rational expressions are fractions with polynomials and are simplified and solved much like regular fractions.