CBSE Class 11-science Answered

Let x denote the breadth of the rectangular piece and y denote the length of the rectangular piece of land.

now according to the question

since the total fencing available is 3000 m ,therefore

                       2x + y = 3000

                    or y = 3000 - 2x

 and the area (A) = xy

therefore   A = x (3000 - 2x)

now if we have to enclose certain area then it has to be greater than zero.

Now ,  x >0 , y > 0 i.e. 3000 - 2x > 0

Which means that 3000 > 2x

 Or   2x < 3000

 Or x < 1500

 But length should be greater than the breadth i.e. y>x

  Which means that   3000 - 2x > x

  Or 3000> 3x

  x < 1000

Now if we see the three bold solution i.e. x < 1000 , x < 1500  and x >0 then on number line we can plot the result as

hence the value of x lies between 0 and 1000

or    0 < x < 1000