SOLUTION: I need help with this question: The area of a rectangular rug is 160sqft. if it's width is 2ft less than 1/2 it's length, find the dimensions of the rug. I know A=LW. I'm racking

Algebra.Com
Question 964189: I need help with this question: The area of a rectangular rug is 160sqft. if it's width is 2ft less than 1/2 it's length, find the dimensions of the rug.
I know A=LW. I'm racking my brain, but this is not my area of expertise. The equation I wrote to find the W is W=L/2-2. then i wrote 160=L(L/2-2), but that isn't getting me anywhere. I need help figuring out how to write the equation to find the dimensions. PLEASE HELP! :-)

Found 2 solutions by josgarithmetic, Alan3354:
Answer by josgarithmetic(39617)   (Show Source): You can put this solution on YOUR website!
Try to work with mostly lower cased letters for the variables.

w, width
L, length (upper case so not to confuse with any digit 1).
A, area of the rug

You already know, .
Translate the description into symbolism.

;
;
.

What do you have?
Basically two equations in the two unknown variables, w and L. Use simple substitution.




At this point you should no longer be "racking" your brain, because you now have a quadratic equation in one single variable, L. You already found this far and then asked for help.




-
Not even trying to factor that, ....
discriminant is .
-
General solution for quadratic equation:


Obviously the PLUS-form makes sense only.


.

Use either the area equation OR the description's formula equation to find w.




Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
The area of a rectangular rug is 160sqft. if it's [sic] width is 2ft less than 1/2 it's [sic] length, find the dimensions of the rug.
I know A=LW. I'm racking my brain, but this is not my area of expertise. The equation I wrote to find the W is W=L/2-2. then i wrote 160=L(L/2-2)
===================
160=L(L/2-2)
Your eqn is correct, just solve it.
320 = L*(L-4)
L^2 - 4L - 320 = 0
(L - 20)*(L + 16) = 0
Ignore the L = -16
---
L = 20
W = 8
==================
PS it's = it is

RELATED QUESTIONS

1. A rocket is fired upward at an initial velocity of 1008 ft/s from a tower that is 120... (answered by amoresroy)
The length of a rectangular sign is 5 feet longer than the width. If the sign’s area is... (answered by lwsshak3)
I need help with this one , i am struggling in this calss and it is about to end and I... (answered by vleith,MathTherapy)
The length of a rectangular rug is 6 feet less than the width. If the aera of the rug is... (answered by nerdybill)
if a rectangular table with an area of 35sq ft has a width that is 2 ft less than the... (answered by checkley77)
the area of a rectangular rug is 60 yd^2. If the width of the rug is 10 yd, what is the... (answered by TimothyLamb)
width of a triangle is 2ft less than the length, area is 24f^2, L=,... (answered by checkley77)
A rectangular rug has a decorative interior with a 1/2 foot border of uniform width... (answered by ankor@dixie-net.com,greenestamps)
The width of a rectangle is 1 ft less than the length. The area is 2ft^2. Find the length (answered by rfer)