It's in the screenshot, please help, there's other questions to if you can help

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 expressions are equivalent to k/2 choose 2 answers: a k-2 b 2/k c 1/2k d k/2 e k+k

What is the slope of the line that contains the points (-2,1) and (0,-3)