What is an expression for the spending money you have left after depositing 1/5 of your wages in savings? Evaluate the expression for weekly wages of $40,$50,$75 and $100

Liz is shipping a package to her friend.the maximum weight of a medium flat-rate box is 20 pounds,including the box which weighs 6 ounces.write and solve an inequality to describe the possible weight ,w, of the contents that liz will ship to her friend if she must use a medium flat-rate box.