Answer:
a) the common difference is 20
b) 
c) the common difference is -13
d) 
Step-by-step explanation:
a) what is the common difference of the sequence xn
Looking at the table, we get x_3=16, x_4=36 and x_5= 56
Deterring the common difference by subtracting x_4 from x_3 we get
36-16 =20
So, the common difference is 20
b) what is x_8? what is x_12
The formula used is: 
We know common difference d= 20, we need to find 
Using
we can find 

So, We have 
Now finding 

So, 
Now finding 

So, 
c) what is the common difference of the sequence 
Looking at the table, we get a_7=104, a_8=91 and a_9= 78
Deterring the common difference by subtracting a_7 from a_8 we get
91-104 =-13
So, the common difference is -13
d) what is a_12? what is a_15?
The formula used is: 
We know common difference d= -13, we need to find 
Using
we can find 

So, We have 
Now finding
, put n=12

So, 
Now finding
, put n=15

So, 
ok so basically x=1/2 which is the exact form. and the decimal form is x=0.5 Step-by-step explanation:
Hello from MrBillDoesMath!
Answer:
The first choice, Pi + (-Pi) = 0
Discussion:
Pi is an irrational number. Saying the irrational numbers <u>are</u> closed under addition means if we add two irrational numbers we will get another irrational number. In our case, Pi + (-Pi) = 0, which is correct, BUT 0 is a <u>rational </u>number. This shows the set of irrational numbers is NOT closed under addition.
Thank you,
MrB
The LCM for 4 and 9 is 36
It’s 20 % hope that helps!