Question

If the length and the breadth of a room are increased by 1 metre each, the area is increased by 21 square metres. If the length is decreased by 1 metre and the breadth is increased by 2 metres, the area is increased by 14 square metres. Find the perimeter of the room.​

Answer 1

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★To find:

Perimeter of room= ?

★Solution :

Let x and y be the length and breadth of a rectangle.

★According to the question,

(x + 1)(y + 1) = xy + 21

(x + 1)(y + 1) - xy = 21.......(i)

Also,

(x + 1)(y - 1) = xy - 5

(x + 1)(y - 1) - xy = -5........(ii)

★Solving these equations we get :

x = 12

y = 7

★Perimeter of Rectangle = 2(12+7)= 38m