If in a rectangle, the length is increased and breadth reduced each by 2 units, the area is reduced by 28 square units. If, however the length is reduced by 1 unit and the breadth increased by 2 units, the area increases by 33 square units. Find the area of the rectangle.
Let the length and breadth of the rectangle be $x$ and $y$ units respectively
Then, area of rectangle $=x y$ square units
If length is increased and breadth reduced each by 2 units, then the area is reduced by 28 square units
$(x+2)(y-2)=x y-28$
$\Rightarrow x y-2 x+2 y-4=x y-28$
$\Rightarrow-2 x+2 y-4+28=0$
$\Rightarrow-2 x+2 y+24=0$
$\Rightarrow 2 x-2 y-24=0$
Therefore, $2 x-2 y-24=0 \cdots(i)$
Then the length is reduced by 1 unit and breadth is increased by 2 units then the area is increased by 33 square units
$(x-1)(y+2)=x y+33$
$\Rightarrow x y+2 x-y-2=x y+33$
$\Rightarrow 2 x-y-2-33=0$
$\Rightarrow 2 x-y-35=0$
Therefore, $2 x-y-35=0 \quad \ldots . .(i i)$
Thus we get the following system of linear equation
$2 x-2 y-24=0$
$2 x-y-35=0$
By using cross multiplication, we have
$\frac{x}{(-2 \times-35)-(-1 \times-24)}=\frac{y}{(2 \times-35)-(2 \times-24)}=\frac{1}{(2 \times-1)-(2 \times-2)}$
$\frac{x}{70-24}=\frac{-y}{-70+48}=\frac{1}{-2+4}$
$\frac{x}{46}=\frac{-y}{-22}=\frac{1}{2}$
$x=\frac{46}{2}$
$x=23$
and
$y=\frac{22}{2}$
$y=11$
The length of rectangle is 23 units.
The breadth of rectangle is 11 units.
Area of rectangle =length $\times$ breadth,
$=x \times y$
$=23 \times 11$
$=253$ square units
Hence, the area of rectangle is 253 square units