SOLUTION: Fred's retangular dog pen must have an area of 400 square feet. Also the length must be 12 feet longer then the width. Find the dimensions of the pen. The width of the pen is

Question 436858: Fred's retangular dog pen must have an area of 400 square feet. Also the length must be 12 feet longer then the width. Find the dimensions of the pen.
The width of the pen is
The length of the pen is
(Simplify your answer. Type a exact answer, using radicls as needed)
Answer by jorel1380(3719) (Show Source): You can put this solution on YOUR website!
Area=LxW
(x+12)x=400
x2+12x-400=0

Solved by pluggable solver: SOLVE quadratic equation with variable

Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=1744 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: 14.8806130178211, -26.8806130178211. Here's your graph:

Throwing out the negative answer, we get width=14.88, and length to be 26.88.
RELATED QUESTIONS
A rectangular dog pen must have an area of 300 square feet. The length must be 50 feet... (answered by ewatrrr)

Oliver is building a rectangular dog pen with an area of 18.9 square feet. If the... (answered by Fombitz)

a rectangular pen for a pet is 7 feet longer than it is wide. Give possible values for... (answered by solver91311)

a dog pen has an area of 60 square feet the width of the pendants two feet shorter than... (answered by Dirichlet)

A friend is building a dog pen with an area of 150 square feet. Each side must be at... (answered by richwmiller)

fence must be retangular. the lengh is 3 feet longer than twice the width. total fencing... (answered by user_dude2008)

An entry in the Apple Festival Poster Contest must be rectangular and have an area of... (answered by lwsshak3)

I'm worse at geometry than I am at algebra, can someone please help me? A rectangular... (answered by jorel1380)

A play ground is 1 yard longer than twice its width. John wants to increase the length... (answered by mananth)