Slope-intercept y=mx+cy = mx + cy=mx+c; point-slope y−y1=m(x−x1)y - y_1 = m(x - x_1)y−y1=m(x−x1); two-point form; intercept form xa+yb=1\dfrac{x}{a} + \dfrac{y}{b} = 1ax+by=1.