if in a rectangle the length is increased and breadth is decreased by two units each, the area is reduced by 28 square units if the length is reduced by 1 unit and breadth is increased by 2 units find the dimensions of the rectangle.
pratik40:
if length is reduced by 1& breadth is increased by 2 units then area is reduced by how many square units?
Answers
Answered by
153
let the dimension be x & y respectively
By the first given condition
(x+2)(y-2)=xy-28
xy-2x+2y-4=xy-28
-2x+2y-4=-28
(multiplying both sides by -1)
2x-2y+4=28
2x-2y=24
x-y=12(divide by 2).................(1)
By the second given condition
(x-1)(y+2)=xy-1
xy+2x-y-2=xy-1
2x-y-2=-1
2x-y=1..........................................(2)
subtracting eqn (2) from (1)
x=-11
substitute x=-11 in eq n(1) x-y=12
-11-y=12
-y=12+11
-y=23
y=-23
SOLUTION:x=-11 ;y=-23
HOPE THIS HELPS
By the first given condition
(x+2)(y-2)=xy-28
xy-2x+2y-4=xy-28
-2x+2y-4=-28
(multiplying both sides by -1)
2x-2y+4=28
2x-2y=24
x-y=12(divide by 2).................(1)
By the second given condition
(x-1)(y+2)=xy-1
xy+2x-y-2=xy-1
2x-y-2=-1
2x-y=1..........................................(2)
subtracting eqn (2) from (1)
x=-11
substitute x=-11 in eq n(1) x-y=12
-11-y=12
-y=12+11
-y=23
y=-23
SOLUTION:x=-11 ;y=-23
HOPE THIS HELPS
Answered by
13
Answer:
let original length=x
and original breadth=y
so, original area of rectangle=length* breadth=xy
According to question
(x+2)(y-2)=xy-28
x-y= 12 - equation (1)
and
(x-1)(y+2) =xy+33
2x-y=35 - equation (2)
subtract equation (1) from (2) :-
2x-y=35
-x+y=12
x=23
put x=23 in equation (1)
23-y=12
y=11
now, length=23m
breadth=11m
Area of rectangle=23*11=253m square.
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