letter d is one of the irrational numbers
<span>the limits as x approaches from the left and right of 1 is not equal.</span>
area = width * length
or
A = W * L
55 = W * (W+6)
solve for width:
0 = W^2 + 6W - 55
this is a quadratic and has two solutions -11 and 5
a length can only be non-negative so discard -11.
width W = 5 miles
now the length is 5+6 = 11 miles
