Math - Expressions

Math expressions is a combination of numbers, variables, operators and etc... that represents a value.

• Term: a single mathematical expression. (2x, 3³, -4)
• Variable: a symbol that represents a number or value. (x, y, z)
• Constant: a fixed value. (1, 2, 3)
• Coefficient: a value that multiply a variable. (2x, -3y, -1x)
• Operator: a symbol that represents a mathematical operation. (+, -, ×, ÷)

Algebraic Expression (wikipedia)

Simplifying and Combining like terms

You can simplify and combine like terms by grouping together the ones that are alike.

Examples

3x + 5x − 2x

$3x + 5x - 2x\\ 8x - 2x\\ 6x$

7x + 4y − 2x + 5y − 3

$7x + 4y - 2x + 5y - 3\\ 5x + 4y + 5y - 3\\ 5x + 9y - 3$

x(2x + 3) − 3(4 − x)

$x(2x + 3) - 3(4 - x)\\ 2x^2 + 3x - 12 + 3x\\ 2x^2 + 6x - 12$

How to simplify a big expression by combining like terms (youtube)