SOLUTION: The area of a rectangular pool is 300 square feet. The length of the pool is 5 feet more than the width of the pool. What is the length of the pool? (Can I see how you solver it pl

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The area of a rectangular pool is 300 square feet. The length of the pool is 5 feet more than the width of the pool. What is the length of the pool? (Can I see how you solver it pl      Log On


   



Question 1171302: The area of a rectangular pool is 300 square feet. The length of the pool is 5 feet more than the width of the pool. What is the length of the pool? (Can I see how you solver it please?)
Found 2 solutions by ikleyn, Alan3354:
Answer by ikleyn(52788) About Me  (Show Source):
You can put this solution on YOUR website!
.

x for the length,

(x-5) for the width.


The area equation is


    x*(x-5) = 300.


It is your basic equation to be solved.


Reduce it to the standard form of a quadratic equation


    x^ 2 - 5x - 300 = 0     (*)


From this point, you can solve this equation in 2 (two) ways.


One way is to apply the quadratic formula


    x%5B1%2C2%5D = %285+%2B-+sqrt%285%5E2+%2B+4%2A300%29%29%2F2 = %285+%2B-+sqrt%281225%29%29%2F2 = %285+%2B-+35%29%2F2,


which gives you two roots x= %285+%2B+35%29%2F2 = 40%2F2 = 20  and  x = %285+-+35%29%2F2 = -30%2F2 = -15.


Of these two roots, only positive x = 20 makes sense.



The other way to solve quadratic equation (*) is to factor its left side

    (x-20)*(x+15) = 0.


It gives the same two roots, of which you chose the positive value x= 20.


So, your ANSWER is: the length of the pool is 20 feet.

Solved and explained. And completed.


With so detailed explanation, everything should be clear to you.


To see many other similar solved problems, look into the lesson
    - Problems on the area and the dimensions of a rectangle
in this site.

Learn the subject from there.


Happy learning (!)




Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The area of a rectangular pool is 300 square feet. The length of the pool is 5 feet more than the width of the pool. What is the length of the pool? (Can I see how you solver it please?)
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Find a pair of factors of 300 that differ by 5.