When the discount period started, the price of a chair changed from $220 to $154 . by what percent did the price of the chair decrease?

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%.

Consider the function f(x)=-5x+3 what is f(-2)

Im so bad at fractions they are not my best math thing to work on