Answer:

Step-by-step explanation:
Given

Required
Determine the formula
First, we need to solve common difference (d)

Take n as 2



Represent each function as a sum of the previous





Represent the function as 

Reorder

Step-by-step explanation:
4x2 - 25b2
We can solve it by the squares so
(2x - 5b) (2x + 5b)
2) x2 - 81
The same case is here so
(x - 9) (x + 9)
Answer:
I think its b and c
Step-by-step explanation:
good luck
Answer:
I think $190,7 cause you have to find the percentages of the taxes and handling fee then add it to her accurate price.
Geo is
an=a1r^(n-1)
2nd term is 12
4th term is 4/3
a2=a1r^(2-1)=12
a2=a1r=12
a4=a1r^(4-1)=4/3
a4=a1r^3=4/3
we have
a1r=12 and a1r^3=4/3
(a1r^3)/(a1r)=r^2=(4/3)/12=1/9
1/9=r^2
sqrt oth sides
1/3=r
the common ratio is 1/3