# Chapter 1

## 16 terms

### Natural Numbers

The set of numbers 1, 2, 3, 4, ... Also called counting numbers.

### Whole Numbers

Natural numbers ( counting numbers) and zero; 0, 1, 2, 3...

### Integers

Natural numbers,their opposites, and zero..-2,-1,0,1,2..Etc

### Rational Numbers

All numbers that can be written as quotients of integers.

### Irrational Numbers

Numbers that cannot be expressed as a ratio of two integers. Their decimal expansions are nonending and nonrepeating. Also not perfect squares.

### Variable

Letter that represents a number

### PEMDAS

Order of operations

### Term

A Variable,a number or the product of those

### Coefficient

A Numerical factor of a term

### Compound Inequality

A pair of inequalities joined by "and" or "or"

### Extraneous Solution

A solution of an equation derived from an original equation that is not a solution of the original solution

a + (-a) = 0
a times 1/a = 1

a + 0=a
a times 1 = a
0 + a = a
1 times a = a

a+b=b+a
ab=ba

(a+b)+c=a+(b+c)
(ab)c=a(bc)

a(b+c)=ab=ac