SOLUTION: Ella needs to make a garden plot which has an area less than 18ft^2. The length should be 3ft longer than the width. What are the possible dimensions of the box?

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Ella needs to make a garden plot which has an area less than 18ft^2. The length should be 3ft longer than the width. What are the possible dimensions of the box?      Log On


   



Question 1169994: Ella needs to make a garden plot which has an area less than 18ft^2. The length should be 3ft longer than the width. What are the possible dimensions of the box?
Answer by ikleyn(52926) About Me  (Show Source):
You can put this solution on YOUR website!
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Let x be the smaller dimension, in meters (the width).


Then the larger dimension (the length) is (x+3) meters, according to the condition.



They want you determine x in a way to satisfy inequality

    x*(x+3) < 18.


It is equivalent to 

    x^2 + 3x - 18 < 0,


or, in factored form

    (x+6)*(x-3) < 0.


The solution to this inequality is the set

    -6 < x < 3.


But due to meaning of x, the dimension x must be positive.


Therefore, the final solution is the set of real numbers  0 < x < 3 meters.


ANSWER.  The width must be shorter than 3 meters;  the length is 3 meters greater than the width.

Solved.