1. **State the problem:** Find the equation of line N in the form $y = mx + c$ given it crosses the y-axis at 20 and passes through the point $(1, 35)$. 2. **Recall the formula:** The equation of a line is $y = mx + c$ where $m$ is the slope and $c$ is the y-intercept. 3. **Identify known values:** The y-intercept $c = 20$ because the line crosses the y-axis at 20. 4. **Calculate the slope $m$:** Use the two points $(0, 20)$ and $(1, 35)$. $$m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{35 - 20}{1 - 0} = \frac{15}{1} = 15$$ 5. **Write the equation:** Substitute $m = 15$ and $c = 20$ into $y = mx + c$. $$y = 15x + 20$$ 6. **Final answer:** The equation of line N is $y = 15x + 20$.