$(10)$ Let $f(x)=\frac{x^2-25}{5-x},$ use table to make a conjecture about the values of

$\backslash$table$[[x,4\mathrm{.}9,4\mathrm{.}99,4\mathrm{.}999,5\mathrm{.}001,5\mathrm{.}01,5\mathrm{.}1],[f(x),,,,,,],[,,,,,,],[,,,,,,]]$

a$)\underset{x{5}^{}}{lim}f(x)=$

b$)\underset{x{5}^{-}}{lim}f(x)=$

c$)\underset{x5}{lim}f(x)=$