Problema Solution

A garden measuring 12 meters by 21 meters is to have a pedestrian pathway installed all around it, increasing the total area to 468.16 square meters. What will be the width of the pathway?

Answer provided by our tutors

let


x = width of the pathway


the area of the rectangle = width * length


then the total area = to the area of the rectangle with width and length (12 + 2x) and (21 + 2x) that is


(12 + 2x)*(21 + 2x) = 468.16


4x^2 + 66x + 338 = 468.16


by solving the quadratic equation we find 2 solution


x1 = 2.8


x2 = -19.3


since the width of the pathway can only be positive number the answer is 2.8 m:


the width of the pathway will be 2.8 m.