SOLUTION: Perimeter of a rectangle. A rectangle has a fixed width and a variable length. Let P represent the perimeter and L represent the length. P = 28 inches when L = 6.5 inches and P

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Perimeter of a rectangle. A rectangle has a fixed width and a variable length. Let P represent the perimeter and L represent the length. P = 28 inches when L = 6.5 inches and P       Log On


   

Question 353592: Perimeter of a rectangle. A rectangle has a fixed width
and a variable length. Let P represent the perimeter and L
represent the length. P = 28 inches when L = 6.5 inches
and P = 36 inches when L = 10.5 inches. There is a linear
equation that expresses P in terms of L.
a) Find the equation.
b) What is the perimeter when L = 40 inches?
c) What is the length when P =215 inches?
d) What is the width of the rectangle?
Answer by sofiyac(983) About Me  (Show Source):
You can put this solution on YOUR website!
d) P=2L+2W, so we can easily find the width since it doesn't change by plugging in P=28 and L=6.5 and solving for W
28=2*6.5+2W
28=13+2W
15=2W
7.5=W So now we know what Width is.
a) The equation that expresses P in terms of L is P=2L+2W
b) P=2*40+2*7.5=80+15=95
c) 215=2L+2*7.5
215=2L+15
200=2L
100=L