All please

$\underset{x}{lim}\frac{5x^4+8x^2}{3x^2-16x^2}$ is

$($a$)-\frac{1}{2}$

$($b$)0$

$($c$)1$ to

$($d$)\frac{5}{3}$

Let the function $f$ be defined by:

$f(x)=\{\begin{array}{ccc}{x}^2+2& \text{f}\text{o}\text{r}& x3\\ 6x+k& \text{f}\text{o}\text{r}& x>3\end{array}$

If $f$ is continuous at $x=3,$ what is the value of $k?$

$($a$)-7$

$($b$)2$

$($c$)3$

$($d$)7$

$3.$ The fizure below slows the graph of the function $f.$