is it linear? Check the picture below, it looks like the graph of a LINE, so yes.
hmm so let's pick two points off the table, say (-9, -2) and (-1, -12) to get the equation
[tex]\bf (\stackrel{x_1}{-9}~,~\stackrel{y_1}{-2})\qquad (\stackrel{x_2}{-1}~,~\stackrel{y_2}{-12}) \\\\\\ slope = m\implies \cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{-12-(-2)}{-1-(-9)}\implies \cfrac{-12+2}{-1+9} \\\\\\ \cfrac{-10}{8}\implies -\cfrac{5}{4}[/tex]
[tex]\bf \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-(-2)=-\cfrac{5}{4}[x-(-9)] \\\\[-0.35em] ~\dotfill\\\\ ~\hfill y+2=-\cfrac{5}{4}(x+9)~\hfill[/tex]
