The local humane society is restocking on cat food to prepare for kitten season. Very young kittens need kitten formula which costs $3.99 per bottle. Older kittens need wet cat food which costs $1.50 per can. Part A: Write an algebraic expression to describe how much the humane society will spend preparing for kitten season. Identify the parts of the expression by underlining the coefficient(s), circling the constant(s), and drawing a box around the variable(s). Part B: How much money (before tax) will the humane society spend if they buy 30 bottles of kitten formula and 120 cans of wet cat food? Part C: If you add a 7% sales tax to the purchase of bottles of kitten formula and cans of wet cat food, how would the algebraic expression in parts A and B change?