# Intro to Col. Algebra: Ch.1 & 2

## 29 terms

1, 2, 3,...

0, 1, 2, 3,...

### Integers (ℤ)

-3, -2, -1, 0 1, 2, 3,...

### empty set (null set); {} or ø

does not contain any elements

### Rational Number (ℚ)

every rational number can either repeat or terminate; 1/2=0.5, 5/4=1.25, 2/3=0.666666, 1/11=0.090909

### Irrational Number (I)

decimal neither terminates nor repeats; 3, 0, -8, π≈3.141592..., 1.414213...,

### Imaginary Numbers (X)

Complex #s with no real part; 5i, -i√14, √-9=3i, πi,

### Complex Numbers (ℂ)

A real # plus/minus an imaginary # and all numbers; 3+2i, 1/2-i√3/2, 5, 0, -6, 2/3, .4=2/5

### Element of (∈)

#s, variables, points, or any other object in a set; A={2,4,6,8}, 4∈A, 6∈A, 2∈A, 8∈A

### Not an element of (∉)

#s, variables etc. not in a set; 5∉A, 1∉A

### Subset of (⊆)

all elements of one set are contained within another set; {a, e} ⊆ {a,b,c,d,e,f}, {2] ⊄ {1,3,5,7}

### Real Numbers (ℝ)

All #s on a line (negatives and positives)

### multiplication phrases

product, times, multiply, twice, of

### division phrases

quotient, divide, into, ratio

8x+3

x ÷ -7 or x/-7

### One and six-tenths subtracted from twice a number

2x-1.6 or 2x-1 6/10

x-6

2(4+x)

a+0=0+a=a

### Multiplication Property

a•1=1•a=a

a+ (-a)= (-a)+a=0

a•1/a= 1/a•a=1

a+b=b+a

### Commutative Property of Multiplication

a•b=b•a

(a+b)+c= a+ (b+c)

(a•b)•c=a•(b•c)

### I=PRT

Interest=principal•rate•time

A=P(1+r/n)nt