When constructing a perpendicular line through a point on a line, how can you verify that the lines constructed are perpendicular?

At the electronics store you have a coupon for 20% off up to 2 cds you buy for cds with the original cost of $10.99 each the sales tax is 5% what is the total cost of your purchase

Aline passes through 3,7 and 6,9 what equation represents the line

Oliver had $50 on the day before his birthday. after he recived some money for his birthday , he had $75. write and solve eqaution to find how much money oliver received for his birthday. x+50=75