Math Unit 2

Constant

A fixed value. In Algebra, a constant is a number on its own, or sometimes a letter such as a, b or c to stand for a fixed number. Example: in "x + 5 = 9", 5 and 9 are constants

algebraic expression

A mathematical phrase that contains one or more variables

Coefficient

A number used to multiply a variable. Example: 6z means 6 times z, and "z" is a variable, so 6 is a coefficient. Variables with no number have a coefficient of 1. Example: x is really 1x. Sometimes a letter stands in for the number. Example: In ax2 + bx + c, "x" is a variable, and "a" and "b" are coefficients.

Variable

A symbol for a number we don't know yet. It is usually a letter like x or y. Example: in x + 2 = 6, x is the variable.

Solution

A value we can put in place of a variable (such as x) that makes the equation true. Example: x + 2 = 7 When we put 5 in place of x we get: 5 + 2 = 7 Which is true, so x = 5 is a solution

Equation

An equation says that two things are equal. It will have an equals sign "=" like this: 7 + 2 = 10 − 1 That equation says: what is on the left (7 + 2) is equal to what is on the right (10 − 1) So an equation is like a statement "this equals that"

Inequality

An inequality says that two values are not equal.

Term

In Algebra a term is either a single number or variable, or numbers and variables multiplied together. Terms are separated by + or − signs

Expression

Numbers, symbols and operators (such as + and ×) grouped together that show the value of something. Example: 2×3 is an expression

Inverse operation

The operation that reverses the effect of another operation.

Evaluate

To calculate the value of. Example: Evaluate the cost of each pie when 3 pies cost $6. Answer: $2 each.

Infinite

Without an end. Not finite. Example: There are infinite whole numbers (0, 1, 2, 3, 4, ... )