In a rectangle, if the length is increased by 3 meters and breadth is decreased by 4 meters, the area of the rectangle is reduced by 67 square meters

Solution:

Let the length and breadth of the rectangle be and units respectively

Then, area of rectangle = square units

If the length is increased by  meters and breath is reduced each by square meters the area is reduced by  square units

Therefore,

$x y-67=(x+3)(y-4)$

$x y-67=x y+3 y-4 x-12$

$y y-67=y y+3 y-4 x-12$

$4 x-3 y-67+12=0$

 

$4 x-3 y-55=0 \cdots(i)$Then the length is reduced by  meter and breadth is increased by  meter then the area is increased by  square units

Therefore, 

Thus, we get the following system of linear equation

$4 x-3 y-55=0$

$4 x-y-93=0$

By using cross multiplication we have

 

$\frac{x}{(-3 \times-93)-(-1 \times-55)}=\frac{-y}{(4 \times-93)-(4 \times-55)}=\frac{1}{(4 \times-1)-(4 \times-3)}$

$\frac{x}{279-55}=\frac{-y}{-372+220}=\frac{1}{-4+12}$

$\frac{x}{224}=\frac{f y}{-152}=\frac{1}{8}$

$x=\frac{224}{8}$

$x=28$

and

$y=\frac{152}{8}$

 

$y=19$

Hence, the length of rectangle ismeter,

The breath of rectangle is meter.