Width = 7n - 1.5
Length = 1.5n + 8
Formula
Perimeter = 2(length) + 2(width) or length + length + width + width
Substitution
Perimeter = 7n - 1.5 + 7n - 1.5 + 1.5n + 8 + 1.5n + 8
Simplification
Perimeter = (7n + 7n + 1.5n + 1.5n) + (-1.5 - 1.5 + 8 + 8)
Perimeter = 17n + (-3 + 16)
Result
Perimeter = 17n + 13