SOLUTION: A concrete mixer needs to know how wide to make a walk around a rectangular fountain that is 10 by 15 feet. There is enough concrete to cover 200 square feet. To the nearest tenth

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: A concrete mixer needs to know how wide to make a walk around a rectangular fountain that is 10 by 15 feet. There is enough concrete to cover 200 square feet. To the nearest tenth       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1166935: A concrete mixer needs to know how wide to make a walk around a rectangular fountain that is 10 by 15 feet. There is enough concrete to cover 200 square feet. To the nearest tenth of a foot, how wide should the walk be in order to use up all the concrete?

Answer by ikleyn(52765) About Me  (Show Source):
You can put this solution on YOUR website!
.

The outer dimensions of the walkway are 10+2x by 15+2x feet, where x is the uniform width of the walkway.


So for the area of the walkway we have this equation


    (1+2x)*(15+2x) - 10*15 = 200.


It can be reduced to the quadratic equation


    4x^2 + 32x - 199 = 0.


Solve it using the quadratic formula.

--------------------

To see many other similar solved problems,  look into the lesson
    - Problems on the area and the dimensions of a rectangle surrounded by a strip
    - Cynthia Besch wants to buy a rug for a room
    - Problems on a circular pool and a walkway around it
in this site.

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lesson is the part of this online textbook under the topic
"Dimensions and the area of rectangles and circles and their elements".

Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.