Please assist me with these question. I am having a hard time

Step-by-step explanation:
[tex] \frac{1}{3x} + \frac{7}{ {x}^{2} } + \frac{x + 2}{x} [/tex]
[tex] \frac{x}{ {3x}^{2} } + \frac{21}{3 {x}^{2} } + \frac{3 {x}^{2} + 6x}{3 {x}^{2} } [/tex]
[tex] \frac{ {3x}^{2} + 7x + 21 }{ {3x}^{2} } [/tex]
Choice D