The length of a spring is a linear function of the weight of the object hanging from it. for a particular spring, the length increases by 0.25 inches for every pound hanging from it. when 4 pounds are hanging from it, the length of the spring is 8 inches. how much weight must be hung from this spring for it to stretch to 12.5 inches?

Me its important ! marge runs an ice cream parlor. her speciality is triple chocolate sundaes.she can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . if she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?