How do equation $17$ And $23$

a$.$ use Equation $3\mathrm{.}4$ to find the slope of the tangent line $m_{tan}=f^{\text{'}}(a),$ and b$.$ find the equation of the tangent line to $f$ at $x=a.$

$17.f(x)=2-3x^2,a=-2$

For the following functions $y=f(x),$ find $f^{\text{'}}(a)$ using Equation $3\mathrm{.}5.$

$23.f(x)=x^2+9x,a=2$