perpendicular+lines+Set+6

Prove that these two lines are perpendicular to each other: -21x = 10y+30-x

x-35=3.5x-5y

 Answered by Julia Spandorfer :

__First Equation__ -21x = 10y+30-x first I moved things to their proper places: -10y = 20x + 30 then I divided the equation by -10: y= -2x-3

__Second Equation__ x-35=3.5x-5y first I moved things to their proper places: 5y= 2.5x +35 then I divided the equation by 5 y= .5x + 7


 * These two equations are perpendicular to each other because their slopes are reciprocals, (1/2 and -2/1)**

2. Write the equation of the line that is perpendicular to the line: 5y-225=15/4x

 Answered by Julia Spandorfer : first I moved things to their proper places 5y= 15/4x+ 225 then I divided the whole equation by 5 y= 3/4x + 45

so the perpindicular equation is y= -4/3x + 45