Since slope is calculated using the formula m = StartFraction v 2 minus v 1 Over x 2 minus x 1 EndFraction, the slope of both lines is equivalent to . It is given that the lines are parallel, and we calculated that the slopes are the same. Therefore, parallel lines have the same slopes. StartFraction v minus z Over w minus x EndFraction StartFraction w minus x Over v minus Z EndFraction StartFraction v minus z b Over x minus z a EndFraction StartFraction w minus x a Over v minus z b EndFraction