1. The Rule of a Series/Sequence
Lesson # 30

2. Different ways to show multiplication
1) The way you know , 5X4=20 2) With a dot, 3 4=12 3) With a bracket, 5(3)=15

3. Varibales
When we do not know something in math, instead of using just a “?”.
We use letters!
You can use any letter of the alphabet!

4. The Rule of a Series/Sequence
The rule of a series allows you to:
Calculate a term(y) based on its rank(x)
y= ax+b or t= mn+b
Y and t= term
a or m= common difference, rate of change, slope
X or n= Rank
B= constant, a number

5. Rule of an arithmetic progression:
Term = (common difference) x rank + number
Y= a (x) + b
Common difference, rate of change is found by looking at the terms and seeing what they are going up or down by.
Number or constant = 1st term – common difference

6. Example In the series: 45, 49, 53, 57, … The common difference = 4
The number = first term – common difference
= 45 – 4 = 41
The Rule:
t = 4n + 41
What is the 5th term of this series?
t = 4(5) + 41 =
= 61

7. Example: Rank (x) Term (y) 1 11 2 14 3 17 4 20 What is the rule?
Common difference= 3
Number= 11-3 =8
rule: t=3n+8
What is the 5th term?

8. Home work
Pg 137
#1,2,6,7
Pg 138#8,9
Pg 139 #12