Use the work shown below to write the equation for a line that has a slope of Negative two-fifths and passes through (15, –2). y = mx + b 1. Substitute the known values: negative 2 = negative two-fifths (15) + b. 2. Solve for b: negative 2 = negative 6 + b. b = 4. What is the equation of the line in slope-intercept form? Negative 2 = negative two-fifths x + 4 y = negative two-fifths (15) + 4 y = negative two-fifths x minus 4 y = negative two-fifths x + 4