Question

The area of a rectangular field gets increased by 25 square units if its length is
reduced by 5 units and the breadth is increased by 10 units. If we increase the
length by 8 units and decrease the breadth by 3 units, the area is reduced
by 14 sq units.
i) Find the length and breadth of the rectangular field.
ii) If one tree needs 2 sq units to plant, in which rectangular field how
many trees can be planted.

Answer 1

Step-by-step explanation:

Let, the length=x m.

And, the breadth=y m.

As, the question, (x-5)(y+10)=xy+25

=> xy-5y+10x-50=xy+25

=>10x--5y=(-25). (1)

& (x+8)(y-3)=xy-14

=> xy+8y-3x-24=xy-14

=> 3x-8y=(-10). (2)

Now, (1)×3×-(2)×10 ---->

30x-15y-30x+80y= -75+100

=>65y=25 So, y=25/65