One way to express linear function rules is called slope-intercept form.
Sometimes, f(x)=mx+b is used. In either case, m and b describe the general characteristics of the line. m indicates the slope, and b indicates the y-intercept. The linear function graphed below can be expressed as f(x)=2x+1,
because it has a slope of 2 and a y-intercept at (0,1).