Question

The length of a rectangle exceeds its breadth by 9cm.If length and breadth are increased by 3cm,the area of new rectangle will be 84cm2 more than of the given rectangle. Find the length and breadth

Answer 1

The length of a rectangle exceeds its breadth by 9 cm. If length and breadth are each increased by 3 cm ,
the area of the new rectangle will be 84 cm^2 more than that of the given rectangle. Find the length and breadth of the given rectangle.


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L and L-9 are the original dimensions.

(L+3) and (L-9)+3 are updated dimensions.

Your equation is

(L+3)*(L-6) = L*(L-9) + 84.

It is a quadratic equation.

Simplify it and solve for L. let the breadth be x length: x+9 , breadth: x length and breadth are incresed by 3 so, length: x+9 +3 = x+12 ,breadth: x+3 Gn: the area of the new rectangle = 84 sq. cm Equation: (x+12)(x+3)= 84+ x(x+9) x2 + 15x + 36 = 84 + x2 +9x if we transpose x2to the opposite side then it becomes x2 x2 x2 + 15x + 36 = 84 + 9x Now it becomes 15x+36 = 84 +9x If we transpose 9x to the opposite side it becomes 15x +36 9x = 84 6x +36 = 84 6x = 84 36 6x= 48 x=48/6 x=8 length : 8+9 = 17 breadth= 8