do you not have destroyer? only ask b/c answer IS in the book...
anway...its a distance between two points problem. both cars start at the same point (34th street)
point A = (7, -3)
point B = (3, 5)
distance = sqrt [(x2-x1)^2 + (y2-y1)]
= sqrt [(3-7)^2 + (5-(-3)^2)]
= sqrt [16+64]
= sqrt [80]
= 8.9