Algebra: Variables and Expressions

Front

What is a variable in algebra?

Back

A variable is a symbol, often a letter, that represents a number that can change or vary.

Front

What is an expression in algebra?

Back

An expression is a combination of numbers, variables, and operations (like addition and multiplication) that represents a value.

Front

Evaluate the expression: 3x + 8 if x = 2.

Back

14

Front

Evaluate the expression: 2r + 1 if r = 3.

Back

7

Front

Evaluate the expression: 7y - 3y for y = 2.

Back

8

Front

Evaluate the expression: 3u + 12 if u = 7.

Back

33

Front

Evaluate the expression: 4y - 5 if y = 6.

Back

19

Front

What does it mean to evaluate an expression?

Back

To evaluate an expression means to calculate its value by substituting the variables with given numbers.

Front

What is the difference between a variable and a constant?

Back

A variable can change its value, while a constant has a fixed value.

Front

What is the order of operations in algebra?

Back

The order of operations is Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right), often abbreviated as PEMDAS.