Question 871470
80 and 60 dimensions of lot.

Lot, 80*60 is the area.
Let w = uniform width surrounding the factory.
Factory area = (80-2w)(60-2w).


Factory and lawn of uniform width are equal in area.  Think carefully about this.  The lot area is TWO times the factory area.


{{{(80*60)/((80-2w)(60-2w))=2}}}
Or depending how best you think this,
{{{80*60=2(80-2w)(60-2w)}}}


Solve for w and use the value to find the dimensions of the FACTORY.