The image provided contains a question regarding finding the equation of a straight line based on the given graph.

Here's a summary of the steps:

1. Calculate the gradient of the line: Two points on the line are given: (0, 4) and (2, 8). The gradient (slope) formula is: $m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{8 - 4}{2 - 0} = \frac{4}{2} = 2$ So, the gradient $m = 2$.

2. State the y-intercept of the straight line: The y-intercept occurs when $x = 0$. From the point (0, 4), we see that the y-intercept is 4.

3. Write the equation of the line in the form $y = mx + c$: Using the gradient $m = 2$ and the y-intercept $c = 4$, the equation of the line is: $y = 2x + 4$

This is the required equation of the straight line.

Would you like any additional details or clarifications on this? Here are five relative questions:

1. How do we generalize the equation of any straight line?
2. What does the gradient represent geometrically on a graph?
3. Can you explain why the y-intercept occurs when $x = 0$?
4. How would the equation change if the line had a negative gradient?
5. How do we find the x-intercept from the equation of a straight line?

Tip: When finding the gradient of a line, always ensure you're using two distinct points on the line and applying the formula correctly to avoid sign errors.