Ron is planning for the back-to-school rush at his store. Last year he estimated that he would need 168 notebooks, but he sold 200 notebooks. What was the absolute error in Ron’s estimate? The absolute error is .

Where m is the slope of the line and b is the y-intercept of the line, or the y-coordinate of the point at which the line crosses the y-axis. to write an equation in slope-intercept form, given a graph of that equation, pick two points on the line and use them to find the slope. this is the value of m in the equation.