Question

The length of a rectangle is 7m more than its breadth. If the length is decreased by 10m and breadth is decreased by 3m, then the area is decreased by 108sq. m. Find the length and breadth of the rectangle.

Answer 1

L=b+7
Therfore area=b(b+7)
=b²+7b

New l=b-3
And new b=b-3
Area=(b-3)(b-3)=b²-6b+9

Then new area=lb-108

Now
B²+6b+9=b²+7b-108
7b-6b=108+9
B=117

And L=B+7=117+7=124



Hope it helps..!

Answer 2

let b=x
l=x+7
area=x (x+7)

new l=x+7-10=x-3
new b=x-3
new area=(x-3)(x-3)

area-new area=108
x (x-7) - (x-3)(x-3)=108
x^2 + 7x - x^2 - 9 + 6x = 108
13x=117
x=9

length= 16m
breadth= 9m