# Algebra

Definition 1 of 2

Pro Tip 1/3

Not Just Numbers

Algebra uses symbols, often letters, to stand in for unknown numbers in equations. Find the value of 'x' in the equation x + 5 = 9.
Pro Tip 2/3

Problem Solving

Algebra is often about finding the missing numbers that make an equation true. If 3a = 9, what does 'a' equal?
Pro Tip 3/3

Real-World Use

Used for calculating things in real life, like expenses, distances, or time. Price of 5 apples (a) is $10: 5a = 10.