Find each function value and the limit for $f(x)=\frac{5x^3-10x^2}{10x^4+5}.$ Use $-$ or $$ where appropriate.

$($A$)f(-6)$

$($B$)f(-12)$

$($C$)\underset{x-}{lim}f(x)$

$($A$)f(-6)=$

$($Round to the nearest thousandth as needed.$)$

$($B$)f(-12)=$

$($Round to the nearest thousandth as needed.$)$

$($C$)$ Select the correct choice and, if necessary, fill in the answer box to complete your choice.

A$.\underset{x-}{lim}\frac{5x^3-10x^2}{10x^4+5}=($Type an exact answer.$)$

B$.$ The limit does not exist and is neither $-$ nor $.$