Help, I really need to know how to understand this. I’m not asking for you to give me an answer, but please help.

[tex]\bf \begin{array}{rrll} x&~\hspace{4em}y\\ \cline{1-2} 2&\stackrel{2\cdot \frac{5}{2}}{5}\\\\ -2&\stackrel{-2\cdot \frac{5}{2}}{-5}\\\\ -4&\stackrel{-4\cdot \frac{5}{2}}{-10}\\\\ x&x\cdot \frac{5}{2} \end{array}\implies\boxed{y=\cfrac{5}{2}x} ~\hspace{8em} \begin{array}{rrll} x&\hspace{5em}y\\ \cline{1-2} 2&5\\\\ 9 &\boxed{22.5}\\\\ -2&-5\\\\ \boxed{-3}&-7.5\\\\ 0&\boxed{0}\\\\ \boxed{11}&27.5\\\\ -4&-10 \end{array}[/tex]