Question 279120
Vanessa built a rectangular pen for her dogs.  she used an outside wall of the garage for one side of the pen.  she used 20 m of fencing in order to build the other 3 sides to complete the rectangle.  find the dimensions of the pen of the pen if the area of the resulting pen was 48 m^2 

Let one side be x

the other side = 48/x

2x+48/x =20

2x^2+48=20x

2x^2-20x+48=0

x^2-10x+24=0

x^2-6x-4x+24=0

x(x-6)-4(x-6)=0

(x-6)(x-4)=0

x=6 or 4  x=6  since we do not know whcich side of the garage was used  

the dimensions of the pen could be 6m & 8m   or 4 m & 12 m