1. **State the problem:** We need to find the equation of line K in the form $y = mx + c$. 2. **Identify points on the line:** From the graph description, line K passes through points $(0,0)$, $(1,5)$, $(2,10)$, and $(3,15)$. 3. **Calculate the slope $m$:** The slope formula is $$m = \frac{y_2 - y_1}{x_2 - x_1}$$ Using points $(0,0)$ and $(1,5)$: $$m = \frac{5 - 0}{1 - 0} = \frac{5}{1} = 5$$ 4. **Find the y-intercept $c$:** Since the line passes through the origin $(0,0)$, the y-intercept is $$c = 0$$ 5. **Write the equation:** Substitute $m=5$ and $c=0$ into $y = mx + c$: $$y = 5x + 0$$ Or simply: $$y = 5x$$ **Final answer:** The equation of line K is $y = 5x$.