John enlarged one side of his square flower bed by 8 ft to make it into a rectangle. The area of the new flower bed is 3 times the area of the old one. What was the length of the side of the old flower bed.

4 ft.

Step-by-step explanation:

We can consider the orignial square's sides to be x, so area of the original figure:

The new rectangle's sides will be x and x+8, so the area of the new figure will be x^2+8x.

We know that the new area is 3 times the old one. So our equation will be:

x^2+8x=3x^2

our answer will be x=4.

Therfore, the length of the side of the old flower bed is 4 ft.