how do I Write an equation for the proportional relationship for the question about apples and pizza proportionality???

Place the following steps in order to complete the square and solve the quadratic equation,

What is the missing step in this proof ?

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?