Equation of a line passing through point (x1, y1) with slope m is given by y - y1 = m(x - x1) For parallel lines, the slope of the required line is equal to the slope of the given line. x = -3 is a vertical line, therefore, the required line will also be a vertical line since they are parallel. Since the required line passes through point (4, 2), the equation of the required line is x = 4.