from sys import stdin
from math import hypot

T = int( stdin.readline() )
for t in range(T):
  stdin.readline()
  line = stdin.readline().split()
  Ax, Ay, Bx, By = [ int(x) for x in line[:4] ]
  P, Q, R = [ float(x) for x in line[4:] ]
  result = abs(Ax - Bx) + abs(Ay - By)
  Axx, Ayy = (R-Q*Ay)/P, (R-P*Ax)/Q
  Bxx, Byy = (R-Q*By)/P, (R-P*Bx)/Q
  result = min( result, abs(Ax - Axx) + abs(Bx - Bxx) + hypot(Axx-Bxx, Ay-By) )
  result = min( result, abs(Ax - Axx) + abs(By - Byy) + hypot(Axx-Bx, Ay-Byy) )
  result = min( result, abs(Ay - Ayy) + abs(Bx - Bxx) + hypot(Ax-Bxx, Ayy-By) )
  result = min( result, abs(Ay - Ayy) + abs(By - Byy) + hypot(Ax-Bx, Ayy-Byy) )
  print "%.10f" % result