You are looking for the slope and y intercept to complete the equation of the line.
The equation of a line is in something called slope intercept form. That looks like y = mx + b. m represents the slope (measure of how steep a line is, and in which direction it is going) and b represents the y intercept (y coordinate when x = 0). You need to find the slope and y intercept to complete the equation.
First, find the slope. The formula for slope is: m = (y2 - y1)/(x2 - x1) where m is the slope and (x1, y1) and (x2, y2) are points.
Pick any two points on the graph. I will use (-2, 0) and (0, 4). Now use these values to find the slope.
m = (4-0)/(0+2) = 4/2
m = 2
m = 2 means that for every two units the line goes up on the y axis, it moves one to the right on the x axis. 2 will go in your first box.
Now find the y intercept. The y intercept is where the line crosses the y axis - it is the y coordinate when x = 0. Here when x = 0, y = 4, so your y intercept is at 4. 4 goes into your second box.
The equation is y = 2x + 4