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, 
the bottom of the pool is 15 x 30 = 450 sq feet.
you the have 2 walls that are 30 x 5 = 150 x 2 = 300 square feet
then 2 walls that are 15 x 5 = 75 x 2 = 150 square feet
for a total of 450 +300 +150 = 900 square feet
1 can covers 250 sq ft
so 900/250 = 3.6
so you would need 4 cans of paint
Answer:
y = -x + 4
perp: m = 1
y + 4 = x - 3
y = x - 7
Step-by-step explanation:
Answer:
$0.63
Step-by-step explanation: