Algebraic Expressions - Quick Notes

Variables and Constants

• Variables: letters that represent numbers (unknowns); examples: x, y, z
• Constants: actual numbers; examples: 3, 5, -2
• Use: to express quantities with unknowns or fixed values

Algebraic Expressions

• An algebraic expression is formed by combining variables and constants using the operations of addition, subtraction, multiplication, and division
• Examples:
  • 3x
  • 5x+4y
  • 5x^2-4x-1
  • \sqrt{3}x+\sqrt{x^3}
  • x+3+x^2

Terms

• A term is a variable, a constant, or the product of variables and constants
• Examples: 3x^2,\; 4xy,\; 5y^2,\; a^2b
• The denominators of terms can be constants as well as variables (e.g., \frac{3}{x},\; \frac{5}{y})
• In algebraic expressions, terms are connected together with addition or subtraction