Introduction to Algebra: Variables, Expressions & Equations

Key Takeaways

• ✓ A variable is a symbol (usually a letter) that represents an unknown value.
• ✓ An expression combines variables, numbers, and operations without an equals sign.
• ✓ An equation states that two expressions are equal and can be solved.
• ✓ Use inverse operations to isolate the variable when solving equations.
• ✓ Always check your solution by substituting it back into the original equation.