Ten less than 1/2 of a number x is equal to 20

Graph y = -|x| + 2. click on the graph until the correct one appears.

Julie goes to the sports store and spends $40.50 before tax. she buys a pair of shorts for $21.75 and 3 pairs of socks that each cost the same amount. how much does each pair of socks cost? $$

I’m still confused on how to work the percentages