Question

What equation is graphed in this figure?

y - 4 = -⅓(x+2)
y - 3 = ⅓ (x+1)
y + 2 = -3(x – 1)
y - 5 = 3(x - 1)​

Answer 1

to get the equation of any straight line, we simply need two points off of it, let's use those two points in the picture below.

`(\stackrel{x_1}{0}~,~\stackrel{y_1}{2})\qquad (\stackrel{x_2}{1}~,~\stackrel{y_2}{5}) ~\hfill \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{5}-\stackrel{y1}{2}}}{\underset{run} {\underset{x_2}{1}-\underset{x_1}{0}}}\implies \cfrac{3}{1}\implies 3 \\\\\\ \begin{array}c \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_2=m(x-x_2) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_2}{5}=\stackrel{m}{3}(x-\stackrel{x_2}{1})`

keeping in mind that for the point-slope form, either point will do, in this case we used the second one, but the first one would have worked just the same.