Answer:
[tex]\sf y=\dfrac{1}{3}x[/tex]
Step-by-step explanation:
First find the slope:
[tex]\sf slope\:(m)=\dfrac{change\:in\:y}{change\:in\:x}=\dfrac{4-5}{12-15}=\dfrac{1}{3}[/tex]
Use the point-slope form of linear equation: [tex]\sf y-y_1=m(x-x_1)[/tex]
(where m is the slope and (x₁, y₁) is a point on the line)
with the found slope and one of the points:
[tex]\begin{aligned}\sf y-y_1 &=\sf m(x-x_1)\\\\\implies \sf y-4 &=\sf \dfrac{1}{3}(x-12)\\\\\sf y-4 &=\sf \dfrac{1}{3}x-4\\\\\sf y &= \sf \dfrac{1}{3}x\end{aligned}[/tex]
