The answer is m = 250 - 25w.
This is because this answer is in y=mx+b format (slope-intercept form) and has the correct values.
In slope-intercept form, m is the slope and b is y-intercept.
In m = 250 - 25w, the y-intercept is 250 and the slope is -25.
This matches the graph.
Y-intercept is where a line crosses the y-axis, which is 250 in this case.
The slope is negative since the values are decreasing over time (as x-values increase, y-values decrease).