A rectangular parking lot is 30 units long and 20 units wide. An equal no. of units are to be added to the length and to the width so that the area of a lot is doubled. Find the dimension of new parking lot.

Explanation

Area of rectangular park ` = 30**30 = 600` square units

Let `x` unit of length and width is added, then,

Area of new rectangular park ` = (30+x)(20+x)` square units

New area is double than previous area,

`:. (30+x)(20+x) = 2**600`

`=>x^2+50x+600-1200 = 0`

`=>x^2+50x-600 = 0`

`=>x^2+60x-10x-600 = 0`

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