PLS HELP ILL REWARD A LOT

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

Which point-slope form equation represents a line that passes through (3,-2) with a slope of -4/5

Arace is 10 kilometers long.markers will be placed at the beginning and end of the race course and at each 500 meter mark.how many markers are needed to mark the course for the race?