SOLUTION: Please can you help me with this problem. I really do appreciate your help... The width of a rectangle is 6 kilometers less than twice its length if its area is 80 square kilo

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Question 607174: Please can you help me with this problem. I really do appreciate your help...

The width of a rectangle is 6 kilometers less than twice its length if its area is 80 square kilometers find the dimensions of the rectangle?

Found 3 solutions by MathLover1, lwsshak3, solver91311:
Answer by MathLover1(20849)   (Show Source):
You can put this solution on YOUR website!

you are given:
The width of a rectangle is less than twice its length }
means:
you know that the area of a rectangle is
and, you also know that the area is
so, use

...plug in all known values

..move to the right and you will have quadratic equation to solve for
....use quadratic formula
...., and

....disregard negative value because the length cannot be negative

......now we can find the
...plug in

check:

Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website!
The width of a rectangle is 6 kilometers less than twice its length if its area is 80 square kilometers find the dimensions of the rectangle?
**
let x=length
2x-6=width
Area=length*width
80=x(2x-6)=2x^2-6x
2x^2-6x-80=0
x^2-3x-40=0
(x-8)(x+5)=0
x=-5 (Reject)
or
x=8
2x-6=10
ans:
length=8 km
width=10 km

Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!

Let represent the measure of the length. Then the width is .

The area of a rectangle is the length times the width so:

Distribute, put the quadratic in standard form, and solve by factoring (hint: divide the whole thing by 2 before factoring). Discard the negative root. Once you know the value of , calculate

John

My calculator said it, I believe it, that settles it