Arectangular garden is fenced on all sides with 256 feet of fencing. the garden is 8 feet longer than it is wide. find the length and width of the garden.

This is a bit of algebra.. you do not know either side so the width you will label x and the length you will label x +8. we know that if you add all 4 sides, you will have 256 feet. x + x + (x+8) + (x+8)=256  4x+16=256, Subtract 16 from both sides and you have 4x=240. divide by 4 on both sides and you get. x=60.. That makes the width = 60ft and the length = 68ft 

Do you need with the x value for the minimum? its always between the two intercepts for a parabola