How is this problem set up to solve? a bottle of the medicine contains 0.5 kilograms of the medicine. one dose of the medicine is 20 grams for a child and 45 grams for an adult. the number of grams used can be calculated with the formula 20c + 45a, where a is the number of adult doses and c is the number of child doses. if a medical assistant needs to give a dose of the medicine to 12 adults and 10 children, will there be enough medicine in the bottle? if not, how many more grams will be needed?