The equation of a straight line can be found using the slope-intercept form of the equation:

$y = mx + b$

Here, $m$ is the slope of the line, and $b$ is the y-intercept (where the line crosses the y-axis).

Steps to Solve:

1. Find the slope ($m$): Slope is calculated as: $m = \frac{\Delta y}{\Delta x}$ From the graph, the line passes through two points: $(0, 4)$ and $(4, 0)$. Using these points: $m = \frac{0 - 4}{4 - 0} = \frac{-4}{4} = -1$

2. Identify the y-intercept ($b$): The line crosses the y-axis at $b = 4$.

3. Write the equation: Substitute $m = -1$ and $b = 4$ into the slope-intercept form: $y = -x + 4$

Final Answer:

The equation of the line is: $y = -x + 4$

Let me know if you'd like further clarification or a different approach.

Here are 5 related questions for further practice:

1. How do you find the slope of a line from two points?
2. What is the significance of the y-intercept in a linear equation?
3. How can the slope-intercept form be converted to standard form?
4. What happens to the graph if the slope is positive instead of negative?
5. How can we verify if a point lies on a given line?

Tip: Always double-check your slope by selecting two points far apart on the line for better accuracy.