7 1/3
I think this is it, i would like for u to get a second opinion.
Answer:



Step-by-step explanation:
We are given the following recursive formula:

And consider 
a2

a3

a4

The equation of the line is x=4
Let's represent the numbers by : x, x+1, x+2, x+3
x+x+1+x+2+x+3=40 The third number in the sequence is x+2
4x+6=40 8.5+2=10.5
4x+6-6=40-6 Therefore the third number in the sequence is
4x=34 10.5
4x/4=34/4
x=8.5
The number of shelves stephen can make is approximately 27
<h3><u>Solution:</u></h3>
Given that Stephen makes wooden shelves for his room
Stephen wants to make the shelves 3/4 foot long
He starts with a board that is 20 feet long
To find: number of shelves he can make
So the number of shelves stephen can make can make is found out by dividing 20 feet long board by 3/4 foot long


So the number of shelves stephen can make is approximately 27