Answer:
[tex]Perimeter= 13n+15[/tex]
Step-by-step explanation:
We know that
Length(l) = 1.5n + 9 ft
Width(w) = 5n - 1.5 ft
The formula for the perimeter(P) of a rectangle is:
[tex]P=2l+2b \\or \\P=2(l+b)[/tex]
So by substituting l and w we get :
[tex]P= 2[(1.5n+9)+(5n-1.5)][/tex]
[tex]P= 2[(1.5n+9)+(5n-1.5)][/tex]
[tex]P= 2[1.5n+5n+9-1.5][/tex]
[tex]P= 2[6.5n+7.5][/tex]
[tex]P= 13n+15[/tex]