#### Answer

$k'(x)=4-6x^{-2}$

#### Work Step by Step

First you have to re-write this number before you can take its derivative. You re-write it as $\frac{3x^2}{x}+\frac{19x}{x}+\frac{6}{x}$ Then you re-write it again as $4x+19+6x^{-1}$ Then you can take the derivative of that number by applying the derivative rule. A number with an x variable, you take the exponent, multiply it with the number in front, then subtract one from the exponent.