The equation of a line in slope-intercept form is:
y = mx + b
where m is the slope and b is the y-intercept.
The slope of the line that passes through the points (x1, y1) and (x2, y2) is computed as follows:
From the graph, the trendline passes through the points (0, 5) and (1, 15), then its slope is:
The trendline intercepts the y-axis at y = 5, then b = 5
Substituting m = 10 and b = 5 into the equation, we get:
y = 10x + 5