An electrician charges an hourly rate of $60, but also charges a fixed fee for making house calls regardless of time spend on the job. One day, the electrician earned a total of $350 for a 5 hour job. Write an equation for C', in terms of t, representing the total cost of the electrician's services if the electrician spends t hours at the house working.

Your vet has placed your pet on a diet. the diet is to contain at least 12 mg of fat and at least 14 mg of protein per serving. these requirements are to be obtained from two food sources. source a contains 2 mg of fat and 2 mg of protein per serving. source b contains 1 mg of fat and 3 mg of protein per serving. if source a sells for $1.28 per serving and source b sells for $1.12 per serving, how many servings of each type should be purchased to satisfy the requirements at minimal cost?