Start with the equation of a line
Rearrange it so y is alone on one side
Put it in the form y = mx + b
Identify m as the slope
Identify b as the y-intercept
If given two points, find the slope first using m = (y2 – y1) / (x2 – x1)
Substitute the slope and one point into y = mx + b
Solve for b
Write the final equation as y = mx + b