Question

If the length and breadth of a rectangular room are each increased by 1m, then the area of the floor is increased by 21 sq m. if the length is increased by 1m and breadth is decreased by 1m, then the area is decreased by 5 sq m. the perimeter of the floor is :

Answer 1

(x+1)(y+1)=xy+21
(x+1)(y-1)=xy-5
xy+x+y+1=xy+21
x+y+1=21
x+y-20=0---------(1)
xy-x+y-1=xy-5
-x+y+4=0
x-y-4=0----------(2)

2y-16=0
2y=16
y=8

x=20-8
=12
The fraction is 12/8....

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