Answer to Question #191108 in Math for Lee Teh

Question

When one side of a square is double and the other side is reduced by 2 units,the area of the resulting rectangle is 126 unit² .Find the area, in unit²,of the square.^.

Answer 1

Let x be the side of the square.

$2x(x-2)=126.$

$x-2x-63=0.$

$x=\frac{2+\sqrt{4+4*63}}{2}=9.$

Area of the square: $A=x^2=9^2=81\;unit^2.$