Answer:

Step-by-step explanation:
Given

Required
Write a recursive expression

When n = 1


When n = 2

can be rewritten as

Substitute 3 for f(1)

Express 1 as 2 - 1
----- (1)
When n = 3

can be rewritten as

Substitute 8 for f(2)

Express 2 as 3 - 1
------ (2)
Write out (1) and (2)


Replace 2 and 3 with n in both cases; This gives

Hence;
The recursive is 
It will be 33/74
77-41 = 33 and 33/74 is the correct fraction for the cars that are NOT boxcars
Answer:
Arithmetic sequence
f(n) = 5n + 2
Step-by-step explanation:
f(1) = 7
f(2) = 7 + 5
f(3) = 7 + 5 + 5 = 7 + (2)(5)
f(n) = 7 + (n-1)(5)
f(n) = 7 + 5n - 5
f(n) = 5n + 2
All you do is add up the sides of the walls, and you get your answer.
<3.
OG.