Question 4383
let length of room = l
    width of the room = w
as per the question   l = w + 5'
the perimeter of room = 70'
or 2(l+w) = 70
putting the value of l in the above equation we have
   2(w+5+w) =70
or 2w +5 = 70/2
or 2w = 35 - 5
or 2w = 30
or  w = 30/2
or  w = 15'
so putting the value of w in l
we have length of room = l = w + 5 = 15 + 5 = 20

so length = l = 20 feet
   width  = w = 15 feet  (Ans)