Rosa works out 1 hour each day at the gym. She spends part of that time on the treadmill and the rest of the time on the stair climber. Rosa burns 10 calories per minute on the treadmill and 7 calories per minute on the stair climber. A. Let it be Rosa's time spent on the treadmill in minutes. Write, but do not simplify, an expression for the total number of calories Rosa burns during her workout. Interpret each part of the expression in the context of the situation. B. Simplify your expression from Part A.