2.1 Expressions

2.1 Algebraic Expressions Variables: Variables are used to represent and unknown number. They are often used in order to find the solutions of an equation. They are often a letter from the alphabet. The most common is x. Constants: A constant is just a fancy name for a number like 1 or 5. Algebraic Expression: An algebraic expression is just a combination of numbers and variables combined together using mathematical operations. Expressions do not have an equal sign. Example:

x2  8

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5 6 5

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x3  3 x 2 y  3 xy 2  y 3 Terms: Terms are separated by plus or minus signs in an algebraic expression. In the first example for an algebraic expression, the terms are x2 and -8. Factors: Factors are numbers or variables that are multiplied together. Coefficients: The name coefficient is just a fancy way of saying the number that multiplies the variables or powers of variables. Examples:

The coefficient of 18 z is 18. The coefficient of 3x 2 y is 3.