Question 5482
Let W = Width
Let L = Length

The length is = 5*width:
L=5W

The difference (subtraction) of it's length and width is 9 inches

L-W = 9

Substitute 5W in for the L in the subtraction equation:
{{{5W-W=9}}}
{{{4W=9}}}
divide both sides by 4
{{{w=(9/4) inches}}}
If it's length is 5 times the width, then:
{{{5(9/4)=45/4}}}

The formula for a perimeter is 
P=2L+2W
{{{P=2(45/4) +2(9/4)}}}
{{{P=(45/2)+(9/2)=(54/2)}}} or 27 inches