Part A : The expression is 24h + 25 = H = hours So you substitute 3 hours 24(3)+25 72+25 = 97 So it's $97 dollars for 3 hours with 1 house call. Part B : My evaluation is correct because h represents hours. Since she worked for 3 hours and get 24$ each hour. You times 24 by 3 which gives you 72 and you add 25 for the house call that you got.