(-7.0 + b)/(7.0 + b) - (49.0 + b^2)/(49.0 + b^2 + 14.0*b)
/ 2\ / 2 \ \-49 - b /*(7 + b) + (-7 + b)*\49 + b + 14*b/ ---------------------------------------------- / 2 \ (7 + b)*\49 + b + 14*b/
/ 2\ (-7 + b)*(49 + b*(14 + b)) - (7 + b)*\49 + b / ---------------------------------------------- (7 + b)*(49 + b*(14 + b))