###
variable expression

an expression that contains a variable (a symbol used to represent one or more numbers)

###
numeric expression

an expression, such as 4.50 x 4, that names a particular number

###
simplifying expression

replacing a numerical expression by the simplest name for its value

###
grouping symbols

a device, such as a pair of parentheses, used to enclose an expression that should be simplified first.

###
equation

formed by placing equals sign between two numerical or variable expressions, called the sides of the equation

###
open sentence

sentences containing variables (like the equations 5x - 1 = 9 and y + 2 = 2 + y)

###
domain

the given set of numbers that a variable can represent

###
solution / root

any value of a variable that turns an open sentence into a true statement

###
sum / difference / product / quotient

addition / subtraction / multiplication / division

###
real numbers

any number that is either positive, negative, or zero

###
integers

positive integers, negative integers, and zero

###
whole numbers

zero and all positive integers

###
inequality symbols

used to show the order of two real numbers (< less than, > greater than)

###
opposite

each number in a pair such as 4 and -4

###
absolute value

the positive number of any pair of opposite non-zero real numbers is called the absolute value of each number in the pair

###
solution set

the set of all solutions of an open sentence

### Please allow access to your computer’s microphone to use Voice Recording.

## We can’t access your microphone!

### Click the icon above to update your browser permissions and try again

Example:

### Reload the page to try again!

Reload

## Press Cmd-0 to reset your zoom

## Press Ctrl-0 to reset your zoom

### It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

## Your microphone is muted

### For help fixing this issue, see this FAQ.