Question

The area of rectangle reduced by $160m^2$, if its length is increased by $5cm$ and breadth is reduced by $4cm$. However, if length in decreased by $10cm$ and breadth increased by $2cm$, then the area is decrease by $100m^2$. Find the dimensions of the rectangle.

Answer 1

$lb-(l+5)(b-4)=160.$
$4l-5b=140$...1

$lb-(l-10)(b+2)=100$

$10b-2l=140$....2

Put $l=5b-70$ in 1

$20b-280-5b=140$

$15b=420$

$b=28m$

$l=70m$

Length of rectangle =$70m$

Breath of rectangle =$28m$