Problema Solution

The length of a rectangular cardboard piece exceeds its breadth by 4cm. If length and breadth are each increased by 3cm, the area of the new piece will be 81sq.cm more than that of the given piece. Find the dimensions of the given cardboard piece.

Answer provided by our tutors

let 'b' represent the breadth of the cardboard, then 'b+4' represents its length


area = length * breadth


let 'A' represent the area of the original piece, then 'A+81' represents the area of the extended piece


A = b(b+4)

A+81 = (b+3)(b+4+3)

substituting 'b(b+4)' for 'A':

b(b+4) + 81 = (b+3)(b+4+3)

solving for 'b' we have b=10


the breadth of the original piece is 10cm, its length was 14cm