Bob decides to go into business selling lemonade. He buys a wooden stand for $45 and sets it up outside his house. He figures that the cost of lemons, sugar, and paper cups for each glass of lemonade sold will be 10¢. Which of these expressions describes his cost for making g glasses of lemonade?
Each glass of lemonade costs 10¢, or $0.10, so that g glasses will cost g × $0.10. To this, add Bob’s fixed cost of $45, giving the expression in $45 + $0.1 × g.