Question

if the length of room is increased by 1 meter and decrease by 1 metre the area is increase by 5 square metres if the length and breadth are increase by 1 metre and the and the area is increase by 21 square metre find the perimeter of the room​

Answer 1

Answer:

40 meter

Explanation:

let the length and breadth of a room be x & y

Area of the room =x* y

When the length and breadth of a room are increased by 1 meter, then the new dimensions of the room would me Length:x+1

Width:y+1

New area=(x+1)(y+1)

Since the area is increased by 21 metres,therefore(x+1)(y+1)-xy=21...........(1)

Further when the length is increased by 1 metre,then the area would be (x+1) *y

now when the length is increased by 1 metre, the area is decreased by 5 square meters

(x+1) *y- xy =21- 5...........(2)

Simplifying & solving eqns 1&2 results in x=4 and y=16

Perimeter of the room =2*(length+width)

=2*(4+16)

Ans:40 meter