24 4/5 - 19,5; 7 2/9

To prepare for the university exams, you need to simplify and evaluate the given expressions:

1. 24 4/5 - 19.5: To subtract 19.5 from 24 4/5, we can convert the mixed number (24 4/5) to an improper fraction. 24 is multiplied by 5 and then added to 4, giving us 124 as the numerator. The denominator remains 5. So, 24 4/5 can be simplified to 124/5. Now, we subtract 19.5 from 124/5: (124/5) - 19.5 = (124 - (19.5 * 5)) / 5 = (124 - 97.5) / 5 = 26.5 / 5 The fraction 26.5/5 can be simplified to a mixed number by dividing the numerator by the denominator: 26.5 ÷ 5 = 5.3 (as a decimal) So, the final answer is 5 3/10.

2. 7 2/9: Since this is already in mixed number form, we can keep it as it is.

So, the simplified and evaluated expressions are:

1. 24 4/5 - 19.5 = 5 3/10
2. 7 2/9 (remains the same)