The length and width of the garden will be obtain as follows:
let the length be x ft, the width will be (x+3.5)ft
area of the bed will be:
A=length*width
11.76=x(x+3.5)
11.76=x^2+3.5x
thus
x^2+3.5x-11.76=0
solving this by quadratic formula we get:
x=[-b+/-sqrt(b^2-4ac)]/2a
thus plugging in the values we obtain
x=[-3.5+/-sqrt(3.5^2-4(-11.76*1))]/2
x=[-3.5+/-sqrt59.29]/2
x=[-3.5+/-7.7]/2
x=4.2 or -11.2
thus the length will be x=4.2 ft and the width will be x-3.5=0.7 ft
