Expression in Science

In science, an expression is a mathematical phrase that combines numbers, variables, and operators (such as +, -, *, /) to represent a quantity. Expressions are used to show the relationships between different quantities and to calculate values in scientific equations and formulas.

Key Terms

• Variable: A symbol used to represent an unknown or changing quantity in an expression.
• Operator: A symbol used to indicate a mathematical operation, such as addition, subtraction, multiplication, or division.
• Term: A single number, variable, or a combination of numbers and variables in an expression.
• Coefficient: The numerical factor of a term that is multiplied by a variable.

Examples of Expressions

Here are a few examples of expressions:

1. 3x + 5
2. 2y - 7
3. 4a² - 2a + 9

Study Guide

To understand expressions in science, it's important to:

1. Identify the variables, constants, and operators in an expression.
2. Understand the order of operations (PEMDAS: Parentheses, Exponents, Multiplication and Division from left to right, Addition and Subtraction from left to right).
3. Combine like terms by adding or subtracting terms with the same variables and exponents.
4. Simplify expressions by performing the operations indicated by the operators.

Practice simplifying expressions and solving equations to improve your understanding of expressions in science.