What is the solution set of the system {2x - 3y =19 and 7x +4y = -6?

Astore has clearance items that have been marked down by 60%. they are having a sale, advertising an additional 55% off clearance items. what percent of the original price do you end up paying?

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Segment an is an altitude of right δabc with a right angle at a. if ab = 2, squared 5 in and nc = 1 in, find bn, an, ac.