(b^2-4b-21) / (b^2-11b+28) + 1/b-4
This is not an inequality but, as an expression, it can be simplified.
(b^2 - 4b - 21) / (b^2 - 11b + 28) + 1/(b - 4) =
(b - 7)(b + 3) / (b - 7)(b - 4) + 1/(b - 4) =
(b + 3) / (b - 4) + 1/(b - 4) =
{(b + 3) + 1} / (b – 4) =
(b + 4)/(b – 4)